alternating current (output from the alternator is AC)
arc welding welding method which uses alternating current to provide heat for melting and fusion of metal parts.
a small pump that squirts fuel into throat of carburetor as throttle is opened.
part of electrical system consisting of lights, horn, electrical starter, turn signals, and warning systems.
chemical compounds used to alter characteristics of lubricating oils and fuels.
plastic, fibreglass or metal box mounted between carburetor and air filter. This box provides a volume of still, filtered air for induction into the engine.
use of fins to dissipate heat from part into air.
a device with paper, oiled foam, oiled gauze or wire mesh to prevent entry of dirt or foreign particles into engine through air intake.
finely atomized mist of air and fuel necessary for combustion. This mixture consists of approximately 15 parts air to 1 part fuel (15:1) at cruising speeds.
a crankshaft driven electrical generator that produces alternating current which must be rectified to DC current.
an instrument for measuring current flow in electrical circuits.
(amp) electrical unit used to measure flow.
a type of welding which uses an electric arc to produce necessary heat. Melting of base metal and welding rod to join two parts. Also known as electric-arc welding.
portion of a DC generator housing generating coils.
heat resistant material commonly used in brake and clutch lining. It is a known cancer causing substance if inhaled.
tiny particles of fuel mixed with air, making fine mist.
a transmission not using a manually operated clutch.
frame which uses the engine as a structural member.
the clearance between meshed of two gears.
a clutch release mechanism made of two stamped plates with three or four ramps. As one plate is rotated by clutch cable, balls climb ramps, forcing plates apart. This movement disengages clutch.
an antifriction bearing consisting of inner and outer races separated by hardened steel balls.
an ignition system with a battery as the source of primary ignition current.
an electrical system having a lead-acid battery as a source of power. The battery is recharged by a charging system using either a generator or
capacitive discharge ignition system which uses a battery to supply primary ignition current.
a part in which a journal, shaft or pivot turns or moves.
a piece of tubing used between wheel bearing inner races to prevent unwanted bearing preload as the axle is tightened.
a power grinder with round abrasive stones mounted on either end of a special electric motor, for rough grinding of ferrous metals.
air from carburetor air jet is mixed with fuel in body of needle jet making an air-fuel froth. The mixture is then metered into throat of carburetor by jet needle and needle jet.
when piston rings do not effectively seal combustion pressure, allowing hot gases to blow between rings and cylinder wall. This causes overheating of piston and poor performance.
a machine tool used to accurately enlarge a cylinder bore.
lowest piston position in cylinder.
small cam that pivots in brake backing plate and forces brake shoe into brake
part of a disc brake which holds friction pads and encloses disc. As brake is applied, hydraulic fluid forces a piston in calipers toward disc, causing disc to be pinched between brake pads.
a round, flat disc made of steel or cast iron. It is mounted on outside of wheel hub.
a circular ring of cast iron that is part of wheel hub. It provides a place for brake lining to be applied.
special hydraulic tubing made of steel, plastic and reinforced rubber. Hydraulic brake lines must be capable of withstanding extreme pressure without deforming.
a special high friction material made of asbestos and other materials bonded to brake shoes and brake pad plates. Brake lining produces friction and heat when it is forced against brake drum or disc.
small circular or square asbestos inserts in a wheel caliper. They produce friction and heat when forced against the disc.
a cast aluminum, half-circular shoe that holds a bonded brake lining material. When brake is applied, shoe forces lining into brake drum.
index grooves, tabs, or reference lines to indicate amount of brake lining or pad wear.
type of welding using a brass alloy filler rod.
a vertical port division in a two-stroke cycle engine cylinder which allows use of a large port without danger of ring or piston catching.
a small, rotating cutter mounted in a rotary grinder and used for metal removal (rotary file). Also, sharp, rough area around a drilled hole.
a carburetor using a flat plate between venturi and intake manifold to regulate airflow through carburetor.
valve which allows fluid to flow around normal path of flow, used in oil filters.
components in valve train that rides on cam lobe.
oval shape of a piston to control and compensate for expansion.
protrusion on a camshaft that causes valve train parts to move as camshaft rotates.
flat plate with slots that engage pins on shift forks. As plate is rotated, slots cause shift forks to move sliding gears or dogs, causing engagement and disengagement of gearbox ratios.
shaft with protruding eccentric lobes. As camshaft rotates, lobes cause reciprocating movement of other valve train parts.
device that mixes and delivers proper amount of air and fuel to engine at a ratio of approximately 15 parts air to 1 part fuel.
a one piece wheel made of cast aluminum or magnesium alloy. This design is more rigid than wire spoked wheel.
an aluminum cylinder block cast around an iron cylinder sleeve.
a one piece cylinder assembly made of cast iron with a machined bore.
a piston made by pouring molten aluminum alloy into a mould of desired shape.
inadequate lubrication caused by air taking place of oil in pump.
a device, used in a battery powered capacitive discharge ignition system, that steps up battery voltage to provide high primary ignition voltage.
point at which any object is perfectly balanced.
clutch engaged by centrifugal force as engine speeds up.
cup-shaped centrifugal oil filter mounted to end of camshaft. As oil passes through slinger, centrifugal force removes impurities that are heavier than oil.
use of a chain and sprocket to connect gearbox output shaft to rear wheel.
wear of pins and bushings of a roller or hy-vo chain, causing chain to lengthen.
to bevel an edge of an object or to chamfer edges of port openings in a two-stroke cycle cylinder to prevent piston ring breakage.
a spring-loaded ball or piston valve that allows flow only in one direction.
voltage regulator with solid state electronic devices to regulate charging system output.
a circular clip or snap ring that fits into a groove, used to locate or retain a shaft or component.
an electrical path from a power source, through wire, to components, and back to source.
amount of space between two adjacent parts.
a gearbox with gear ratios spaced close together.
device used to connect and disconnect engine power to gearbox input shaft.
part of clutch assembly containing clutch plates. Primary drive gear engages teeth on outside of clutch basket.
tool to secure clutch basket and clutch hub while loosening or tightening clutch security nut or primary drive gear nut.
part of clutch that engages with plain driven clutch plates. Clutch hub is mounted on gearbox input shaft.
part of a clutch assembly providing pressure against clutch disc or clutch plates.
clutch release mechanism
mechanism that moves clutch pressure plate away from clutch pack, allowing clutch to slip.
thin coating of chrome or iron applied to inside of cylinder by electroplating or wire explosion spray coating.
build-up of a magnetic field while current is flowing through primary windings of coil.
a strong cleaning solvent used to dissolve and remove varnish on carburetor parts.
use of different base colours and coloured tracers on insulation of electrical wire for purpose of identification.
burning of air-fuel mixture in combustion chamber.
area of cylinder head and cylinder above piston where combustion of air-fuel mixture takes place.
same oil is used to lubricate engine, gearbox, and primary drive.
increased pressure caused as volume is reduced. Also, movement of suspension components against spring pressure caused by a force against the wheel.
gauge which measures cranking pressure between piston and upper cylinder.
piston ring designed to seal pressure between piston and upper cylinder.
movement of piston from BDC (bottom dead centre) to TDC (top dead centre) with valves closed, compressing air-fuel mixture for more violent combustion.
when two or more circular parts have same centre line.
two metal sheets separated by an insulator used to store an electrical charge.
a wheel hub (wire wheel) with spoke holes on brake side of wheel at a greater distance from centre of hub than spoke holes on opposite side of hub.
a rod made of steel or aluminum or titanium, usually having an I-beam cross section. It connects piston to crankshaft.
a parts kit consisting of connecting rod, crank pin, thrust washers and roller bearings, used in reconditioning of assembled crankshafts.
amount of radial (side) play at top of connecting rod. Measurement of rod tip is one way of determining condition of rod big end bearing.
switching device used to start and stop flow of current.
a continuous path for current flow.
suspension used on dual-purpose and road bikes which provides less than 6 in. (152 mm) of suspension travel.
projections on cylinder heads, cylinders and crankcases to increase surface area for more efficient heat dissipation into air.
output sprocket from gearbox. Mounted on output shaft in indirect drive gearbox and on high gear pinion in direct drive gearbox.
frame built of tubing which supports and surrounds engine.
castings that support and contain the crankshaft, primary drive and gearbox.
pressure test done to a two-stroke cycle engine to determine if crankcase is properly sealed.
pin or journal on which big-end of connecting rod rides.
extensions at each end of crankshaft to provide a mounting place for main bearings, primary drive or sprocket, and alternator rotor or magneto flywheel.
replacement of worn lower-end components in an assembled crankshaft. This involves pressing crankshaft apart, replacing crankpin, roller bearing, thrust washer, and connecting rod, pressing crankshaft back together and trueing it (assembled crankshaft).
portions of an assembled crankshaft that provides a mounting place for
movement of electrons through a conductor.
a series of events which take place during a specific interval.
a machined hole in cylinder block for piston, open at both ends.
casting attached to crankcase which contains cylinder bore, cooling fins or water jacket, and provides a means of mounting cylinder head.
diameter of cylinder opening.
bore diameter machined (bored) to accept oversized piston. This renews a worn cylinder.
use of a hone to slightly roughen walls of cylinder. It produces a crosshatch pattern which aids in seating of new rings.
casting that seals top of cylinder and provides a mounting place for spark plug. In four-stroke cycle engine, cylinder head also contains intake and exhaust ports. Both two- and four-stroke cycle engines also have combustion chamber built into cylinder head.
use of a parallel type cylinder hone to size a cylinder after boring. Proper cylinder honing provides proper texture and crosshatch.
cast iron sleeve or tube pressed or cast into cylinder block to provide bore which piston moves in.
device which uses oil metered through orifices to control abrupt suspension movement during extension and compression.
tube secured to bottom of each fork slider to hold slider onto fork leg. Damper rod controls movement of front suspension by metering hydraulic fluid through orifices in rod.
to remove carbon build-up on piston, combustion chamber, and other parts.
a precision measuring tool used to take measurements of stepped surfaces.
an oil which keeps particles and contaminants in suspension and has ability to neutralize acids resulting from combustion process.
a condition where excessive temperature of air-fuel mixture in combustion chamber causes uncontrolled explosive burning. As detonated flame front collides with flame front initiated by spark plug, extreme pressure is often heard as "pinging" or "knocking." Detonation can be caused by incorrect ignition timing, lean air-fuel ratio, and improper fuel.
process of determining cause of a failure.
dial bore gauge
a precision measuring tool which combines a telescoping gauge and dial indicator to give readings of inside diameter measurements.
a precision measuring tool used to determine inside, outside, or depth measurements. Measurements are displayed on a dial index.
a precision measuring tool using a dial index to show linear movement of components being measured.
a thin flexible disc of rubberized fabric which separates two cavities and uses vacuum or pressure for activation.
a slightly cone shaped metal disc which acts as a clutch pressure plate spring when flattened.
a projection in base of carburetor venturi and at top of needle jet that aids in fuel atomization.
a solid state electronic device that permits current flow in only one direction.
direct bearing lubrication
an oil injection system which feeds undiluted oil to two-stroke cycle engine main bearings and rod big-end nearing.
a continuous flow of current in same direction.
direct drive gearbox
power is transferred from clutch to input shaft (main shaft), to layshaft, to high gear pinion, which has output sprocket mounted on it.
a brake consisting of a flat circular disc attached to a wheel. A hydraulic or mechanical caliper applies pressure to two brake pads to slow or stop disc rotation.
DOHC (double-overhead camshaft)
two camshafts located in cylinder head (one for intake, one for exhaust).
a drum brake having two leading shoes and no trailing shoes. Each shoe has its own activating cam and pivot.
a hydraulic brake caliper with two pistons and provisions for applying hydraulic pressure equally to both pistons. The caliper body is fixed solidly.
a chain having two rows of rollers. Duplex (double-row) chains are used for primary drives.
a clutch plate which is indexed into clutch basket (outer hub) by tabs. Drive plate has friction material bonded to its surface. When clutch is engaged, drive plate transfers power to driven plate.
a clutch plate which is indexed onto clutch inner hub by tabs or splines around its inside diameter. Driven plate is usually a plain plate (no friction material) and drives gearbox input shaft through clutch inner hub.
a brake consisting of two brake shoes mounted on a backing plate. One or two cams cause shoes to expand against inside of brake drum. Brake drum is part of hub or is bolted to hub.
a clutch assembly that does not run in an oil bath.
in this system, oil is gravity fed to supply side of oil pump from a remote oil tank. After oil has been pumped through fourstroke cycle engine, it is returned to oil tank by return side of oil pump.
dual-rate charging system
a charging system that switches extra coils into charging system when lights are turned on.
length of time, in crankshaft degrees, that ignition contact points are closed.
dykes piston ring
a piston ring with an L-shaped cross section designed to use combustion pressure to improve sealing.
dynamic ignition timing
use of a strobe light to check ignition timing with engine running.
electric arc welding
see arc welding.
conductors at centre and side of spark plug that provide an air gap for an electric arc to start combustion process in engine.
a solution of dilute sulphuric acid used to provide a chemical reaction in a lead-acid battery.
a magnet which produces a magnetic field by passing electrical current through a coil wire wrapped around a soft iron core.
alternator an alternator which uses electromagnet to produce a magnetic field.
electromotive force (EMF)
force that causes electricity to flow because of a difference in potential between two points.
electronic ignition system
an ignition system which uses a magnetic triggering device and solid state amplifier rather than conventional contact points.
a disposable oil or air filter that uses gauze or paper as filtering material.
elliptical port shape
rounded port shape designed to prevent ring catching in large ports of two-stroke cycle engine.
byproducts of a running engine, including: exhaust pollutants, noise emissions.
a roller chain without a master link for connections of ends. All pin links are permanently riveted.
a machine that converts chemical energy into mechanical energy.
English measurement system
a measurement using the foot (12 in.) as a standard.
a carburetor system with a plunger to open and close an air-fuel circuit which discharges a rich mixture into throat of carburetor for cold starting.
eroded piston (crown)
a condition caused by detonation or pre-ignition where temperatures are raised so high that part of piston crown is melted away.
an opening or passage which directs flow of exhaust gases out of engine. In a four-stroke cycle, it is located in the head. With a two-stroke cycle, it is in the cylinder.
exhaust (port) timing
amount of time two-stroke cycle exhaust port is open, expressed in crankshaft degrees or piston travel.
with a four-stroke cycle engine, it is movement of piston from BDC to TDC with exhaust valve open, pushing burned gases out of cylinder.
the return or stretching outward of suspension components (after compression) caused by spring pressure.
a device used to attach one part or assembly to another (nut and bolt, screw, rivet, etc.).
a measuring tool made of steel blades of precise thickness used for measuring distance between surfaces.
a electromagnet used in DC generator or AC generator to produce a magnetic field.
a metal rod that is melted into welding puddle to provide necessary bead thickness.
ability of an oil to keep moving parts from making contact with each other.
chains and sprockets or shafts and gears used to connect the gearbox output shaft to rear wheel.
a carburetor mounted by a flange. The flange is bolted to a manifold on cylinder or cylinder head. An insulator block and a gasket are used to seal and insulate carburetor.
a carburetor device consisting of plastic or hollow brass floats attached to an arm. This assembly pivots on a pin and raises and lowers, opening and closing float needle to control fuel level in float bowl.
level of fuel maintained in carburetor float bowl. Controlled by float, float needle and seat.
float needle and seat
a carburetor valve, opened and closed by the float, that lets fuel into float bowl from fuel line.
fluid pressure gauge
gauge for measuring fluid pressure in a system such as oil pressure or fuel pressure.
a weight attached to an engine crankshaft, providing crankshaft with added inertia. This helps to smooth out abrupt movement of crankshaft during power stroke and to keep crankshaft turning during non-power producing events.
magnet mounted on side of flywheel in a flywheel magneto.
flywheel magneto ignition system
an AC ignition system using a generating coil or a magnetic trigger (CDI) or contact points as well as a flywheel to provide primary ignition current and triggering. An external ignition coil is used to provide secondary current.
undesirable characteristic of oil being whipped into a froth (air and oil solution).
amount of work required to lift one pound one foot, used to express torque.
a piston made by hammering hot aluminum into a mould of desired shape.
outer portion of fork which slides over fork leg inner.
long sturdy tubes usually attached to triple clamps and fitted inside fork sliders. Can also be fitted to front wheel on some modern bikes (upside down forks)
one cycle consisting of four distinct events, intake, compression, power, exhaust. One cycle requires two revolutions of crankshaft.
resistance to movement between two objects contacting each other, causes heat.
see drive plate.
a small filter designed to remove dirt and water from fuel before it reaches carburetor or injection system. Filters may be made of metal or plastic screen, paper and gauze. Filters may be located at fuel tank, in fuel line, or at carburetor.
a flexible fuel resistant hose that carries fuel from fuel petcock to carburetor.
an on-off valve located at bottom of fuel tank. It may provide for reserve fuel supply and may have a filter screen and sediment bowl. Fuel line to carburetor is attached to fuel petcock.
a diaphragm or electric device that maintains proper fuel pressure to carburetor or injection system. A fuel pump must be used when fuel tank is located lower than carburetor and with all injection systems.
system which stores, filters, and regulates flow of fuel to engine. It consists of fuel tank, fuel valve, fuel filters, fuel lines, air filter, carburetor, and carburetor mounting.
a reservoir used to store fuel for delivery to engine.
a rectifier that converts AC to DC by inverting negative portion of AC sine wave.
a device used to protect electrical circuits from overloading. A link in fuse melts and opens circuit if current is above normal rating.
gas-charged shock absorber
a shock absorber using a pressurized gas such as nitrogen to help prevent changes in damping as shock absorber heats up.
a series of shafts and gears which varies ratio of engine to rear wheel speed. Motorcycle gearboxes use from two to seven speeds or ratios.
a plunger and spring or pivoted lever that indexes into dimples or slots in shift drum or cam plate. It provides positive positioning of shift drum or cam plate in each gear.
gear oil pump
an oil pump with gear type teeth to move oil.
ratio of rotation of rotating part compared to another rotating part.
a device which converts mechanical energy into electrical energy, producing direct current (DC).
a container, calibrated in cubic centimetres or millimetres used for accurate measurement of fluids such as fork oil and gearbox oil.
a reinforcing plate or boxed section used to prevent flexing of frame or swing arm.
a rectifier which blocks one-half of AC sine wave to convert AC into DC.
movement of heat from one area to another.
a type of electric arc welding which uses inert gas to shield area around arc.
a gear having teeth that are slightly angled. Helical gears (used for primary drives) are quiet in operation, but absorb a slight amount of power due to side thrust.
hemispherical combustion chamber
a combustion chamber shaped like a round dome, allowing use of large valves placed opposite each other in chamber.
top gear on main shaft in direct drive gearbox. All ratios drive through high-gear pinion, which has output sprocket mounted to it.
a condition caused by severe detonation or pre-ignition, where a hole is eaten or burned through crown of piston as a result of extreme heat and pressure.
a unit for measuring the power of engines, motors, etc.; 1 h.p. equals 550 foot-pounds per second.
a braking system using hydraulic fluid, piston, and cylinders to provide extremely high pressure for brake application.
a system which uses hydraulic pressure to disengage clutch.
a very strong chain made up of toothed plates positioned side by side and held together by pins. Advantage of this type of chain is great strength and quiet operation.
air-fuel ratio with throttle twist grip closed. Idle mixture is controlled by pilot jet and pilot adjustment screw in carburetor or computer in electronic fuel injection system.
a step-up transformer that uses induction to increase battery voltage to over 20, 000 volts.
coil in a flywheel magneto that provides primary ignition current.
part of the electrical system responsible for providing a high voltage at proper time to ignite air-fuel mixture. Battery and coil, electronic, magneto, and CDI are the four systems commonly used.
finned wheel that produces pressure and flow when spun in enclosed housing of oil pump or water pump.
indirect drive gearbox
a gearbox where power is transferred from clutch to input shaft to output shaft. Output shaft has a sprocket mounted on one end.
production of current flow resulting from magnetic field cutting through a conductor.
tendency of a stationary object to resist movement or tendency of a moving object to continue moving in same direction.
an oil pump and oil lines that deliver oil to a two-stroke cycle engine as it is needed. Also, fuel system which meters gasoline into engine intake ports.
cylinders positioned in a row or side by side.
a small fuel or oil filter that replaces a section of line or hose.
shaft of a gear box which carries power into gearbox. Clutch assembly is mounted on gearbox input shaft.
a precision measurement tool used to take accurate measurements of inside surfaces.
a fibre or rubber block that insulates carburetor from engine heat, used with flange-mounted carburetors.
a sleeve or flange made of rubber or metal to attach carburetor to intake port.
an opening or passage that directs flow of air-fuel mixture into engine. In a four-stroke cycle engine, intake port is located in cylinder head. In a two-stroke cycle engine, intake port is located in cylinder or crankcase.
in a four-stroke cycle engine, movement of piston from TDC to BDC with intake valve open, drawing air-fuel mixture into cylinder.
amount of time two-stroke cycle engine intake port is open, expressed in crankshaft degrees or piston position.
internal combustion engine
an engine that burns fuel inside rather than outside engine, as does a steam engine (external combustion engine).
a carburetor component, usually made of brass, which meters flow of fuel to venturi. Fuel is metered by a small hole drilled through centre of jet.
a device that transfers action of a single cable to two or more cables.
parallel-sided piece inserted into groove cut part way into each of two parts, which locates and prevents slippage between parts. Also known as a woodruff key.
keystone piston ring
a piston ring with a tapered cross-section designed to use combustion pressure to aid in sealing.
energy associated with motion. An internal combustion engine produces kinetic energy (crankshaft rotation).
side-to-side movement (wobble) of a wheel rim.
a machine tool used to spin, cut, and shape a metal part with a movable cutting tool.
second shaft in a direct drive gearbox. It transfers power from input shaft to high gear pinion.
an air-fuel ratio that contains extra air compared to fuel.
lever and pivot
a clutch release mechanism in which a pivoted lever attached to clutch cable disengages clutch by pushing plate away from clutch plates, allowing them to slip. Lever and pivot may act directly on pressure plate or through a push rod.
a hard surface shaft with a radius or roller at one end that rides on cam lobe.
use of liquid piped through water jackets, thermostat, and radiator to dissipate heat.
long travel rear suspension
suspension used on current competition dirt bikes to provide more than 6 in. (15 cm) of travel.
portion of an engine from cylinder base downward, including connecting rods.
a thin coating of lubricant (oil) that prevents contact between moving parts.
use of lubricants (oil, grease) to reduce friction.
invisible lines of force surrounding a magnet or a conductor with current flowing through it.
an invisible force that attracts ferrous metals.
see flywheel magneto.
a capacitive discharge ignition using a generating coil in magneto to produce primary ignition current.
main fuel circuit
carburetor circuit that controls air-fuel ratio from three-fourths to full throttle opening. Main jet meters fuel in this circuit.
a carburetor fuel metering jet, usually mounted at base of carburetor body, to control air-fuel ratio from three-fourths to full throttle.
injector oil is pumped into the intake port of two-cycle engine.
components in a braking system that produces hydraulic pressure for system.
a pin link that has one removable side plate located by a clip, or is staked (punched) in place. This allows a convenient way of separating chain.
two or more parts that contact each other during operation and set up wear patterns.
a braking system that uses a mechanical advantage by way of levers and cables or rods to apply brakes. A braking system not using hydraulic fluids or hydraulics.
a disc brake caliper actuated by a lever and cam rather than hydraulic fluid.
mechanical voltage regulator
a voltage regulator using an electromagnet to open or close contact points, varying output of a DC generator or electromagnet alternator.
a measurement system that uses the meter (39.37 in.) as a standard.
mild port timing
two-stroke cycle engine ports open for a relatively short time, providing for a broad power band.
a two-wheeled vehicle powered by an internal combustion engine.
an oil that flows like a thin oil when cold, but lubricates like a thicker oil when hot. For example, 10W40 at 0
a clutch assembly using more than one driving plate and more than one driven plate.
use of many small transfer ports rather than two large ports in two-stroke cycle cylinder. This can give improved scavenging.
an antifriction bearing utilizing hardened steel rollers between hardened races or parts.
carburetor circuit that controls air-fuel ratio from one-fourth to three-fourths throttle opening. The jet needle and needle jet meter fuel flow in this circuit.
with an excess amount of electrons which flow toward positive terminal.
neutral indicator switch
a switch, usually mounted on end of shift drum, which completes circuit of neutral indicator light when gearbox is in neutral.
a kickstart system using gearbox input shaft and clutch hub to connect kickstart lever to crankshaft. For starting, gearbox must be in neutral and clutch engaged.
engine design with separate engine crankcase and gearbox case.
nylon screw clutch release
a clutch release mechanism that uses a coarse, square threaded nylon screw for clutch disengagement.
unit used to measure resistance in an electrical circuit or component.
an instrument that measures resistance.
oil level is just high enough so it splashes around inside case or housing. Lubricates gearbox, primary drive ass well as ring and piston.
oil control ring
piston ring designed to remove excess oil from cylinder wall, usually bottom ring.
a device that provides oil under pressure for engine lubrication.
oil pump bleeding
removal of air from supply line and pump in a two-stroke cycle oil injection system.
a circular, lipped disc used in direct bearing oil injection to feed oil to rod big end.
cylinders positioned opposite each other in same plane.
a ring made of neoprene that is used to provide a positive seal. It usually fits into a groove slightly shallower than O-ring, and mated against a flat surface to provide a seal for oil, fuel, or air.
roller chain that uses O-rings to permanently seal lubricant into area between pins and bushings.
out of roundness
cylinder wear caused by piston thrust. This results in wear to front and back of cylinder. Cylinder wears oval shaped rather than round.
gearbox shaft that transmits power to final drive at a selected ratio.
a precision measuring tool for taking accurate measurements between outside surfaces.
overall gear ratio
ratio of crankshaft revolutions to rear wheel revolutions.
a tube that is open at both ends and mounted in bottom of carburetor float bowl. If float sticks or float needle does not seat properly, excess fuel flow out overflow tube rather than into throat of carburetor.
oil that has been chemically combined with oxygen as a result of excessive heat, oil agitation or exposure to combustion contaminants.
oxyacetylene (gas) welding
a type of welding (metal fusion) which burns a mixture of oxygen and acetylene to provide a high temperature flame.
a circuit where current is provided to each component independently (each component has own ground). The failure of one component does not affect rest of circuit.
permanent magnet alternator
an alternator using permanent magnets to produce a magnetic field for AC production.
pilot air screw
a screw mounted on side of carburetor that allows fine adjustment of air-fuel ratio in pilot circuit of slide type carburetor.
a carburetor circuit that provides proper air-fuel ratio from approximately zero to one-eighth throttle opening. It basically consists of a pilot jet, pilot air screw or pilot fuel screw, and a pilot discharge port.
jet that meters fuel for pilot circuit.
a small gear that either drives or is driven by a larger gear.
a slotted block used to support pistons for cylinder installation. Also, may be used in conjunction with a piston pin to lock camshaft.
piston (braking system)
a moveable part of a master cylinder or wheel caliper. Master cylinder piston produces pressure and caliper piston applies that pressure to brake disc, slowing or stopping wheel.
top of piston, directly exposed to combustion pressure and heat.
a cylindrical part, closed at one end, which moves up and down in cylinder. Open end is attached to connecting rod. Combustion pressure is exerted on closed end of piston, causing connecting rod to move and camshaft to turn.
piston pin boss
a strengthened section of piston extending to inside of piston crown. It supports piston pin.
piston pin hole
machined hole through piston wall where piston pin and retaining circlips are mounted.
two-stroke cycle piston skirt used to control intake port opening and closing.
piston ring (compression)
a split cast iron band, sometimes chrome plated, designed to seal combustion pressure above piston.
piston ring end gap
distance between ends of a piston ring when installed in cylinder. This clearance is measured with a feeler gauge. Ring must be straight in cylinder as if installed on piston.
piston ring groove
groove machined in piston to accept piston rings.
piston ring (oil control)
a split cast iron or steel band used to scrape excess oil from cylinder wall. Sometimes designed as a three-piece unit.
overheating of piston to point where it will no longer move freely in cylinder.
part of piston below bottom ring and pin boss.
a split or circular type bearing in which a part slides, turns, or pivots.
see driven plate.
plunger oil pump
an oil pump that uses a piston, or plunger, and check valves to move oil.
direction of current flow.
port opening in a two-stroke cycle engine cylinder wall.
electrical terminal having a deficiency of electrons and attracts electrons from negative terminal, causing current flow.
positive carburetor linkage
a carburetor linkage designed to positively open and close one or more carburetor throttles, actuated by one cable for opening and another cable for closing.
ability to do work or rate of work being done.
in four-stroke cycle engine, movement of piston from TDC to BDC with intake and exhaust valves closed, after ignition and combustion of compressed air-fuel mixture.
a system of gears, chains, sprockets, and shafts that transfers power from crankshaft to rear wheel in varying ratios.
power transmission shock absorber
a compensator cam, rubber pads, or springs in primary drive, gearbox, drive shaft, or rear wheel, provides means of cushioning loading of gearbox.
premature ignition cause by "hot spots" in combustion chamber that ignite air-fuel mixture before spark plug "fires." This causes uncontrolled combustion and rapidly raises piston and cylinder head temperatures (similar to detonation).
two-stroke cycle engine lubrication provided by oil mixed with fuel in fuel tank.
cast iron cylinder sleeve in interference fit into aluminum cylinder block.
primary chain drive
a primary drive design that uses a chain and sprocket to transfer engine power from crankshaft to clutch.
use of chain, gear, or belt drive to connect crankshaft to clutch and gearbox into shaft.
primary ignition circuit
section of ignition circuit including contact points, condenser, and primary windings of ignition coil, power supply (battery or ignition generating coil), kill switch, ignition switch, and related wiring.
a kickstart system that connects kickstart lever to crankshaft through clutch basket. Gearbox can be in gear for starting if clutch is disengaged.
a gear reduction usually about three to one, accomplished by primary drive.
primary-type needle circuit
fuel metered by clearance between jet needle and needle jet is partially mixed with air from air jet and discharged into venturi of carburetor.
hundreds of turns of wire in an ignition coil to provide build-up and collapse of a magnetic field, including voltage in secondary.
contour or shape of camshaft lobe.
push rod (pushrod)
in four-stroke cycle engine, push rods provide means of transferring tappet movement to rocker arm, which opens valves.
rack and pinion clutch release
a clutch release mechanism using pinion gear and a rack gear to disengage clutch.
up and down movement of a rotating part (wheel rim, flywheel, etc.).
a heat exchanger that reduces coolant temperature in a liquid cooling system.
radical port timing
ports open for a relatively long period of time.
an aluminum case which provides a mounting place for shaft drive ring and pinion gears. This housing is sealed and carries oil that lubricates ring and pinion gears.
weight of any engine parts moving back and forth while engine is running: pistons, rings, piston pin and circlips, push rods, valves.
a device that converts AC (alternating current) into DC (direct current) for battery charging.
an aluminum frame providing a mounting place for reed petals in two-stroke cycle engine.
movable parts of reed valve assembly.
a one-way valve place in intake port of a two-stroke cycle engine. It prevents backward flow of crankcase air-fuel mixture.
a device that controls alternator or generator charging current to battery.
a spring-loaded valve that regulates maximum pressure of enclosed system.
characteristic of an electrical circuit to resist flow of current, measured in ohms.
an air-fuel ratio that contains extra fuel compared to air.
an unworn portion or ledge at the top of cylinder formed above end of ring travel.
distance a wheel rim is set off-centre (lateral) to a wheel hub. Rim offset is sometimes needed for drive sprocket clearance.
a rubber strip installed around centre of a wire wheel rim to protect inner tube from being punctured by spokes.
ring and pinion contact pattern
area of contact between teeth of ring gear and teeth of pinion gear. Checked with red lead.
a large gear in shaft drive housing. It is driven by pinion gear.
solid area of piston which supports rings, located between ring grooves.
a pivoted arm that converts upward movement of push rod to downward movement of valve.
an antifriction bearing consisting of hardened steel inner and outer races, separated by hardened steel rollers.
a chain made up of pins, side plates, bushings and rollers. Roller links are connected by pin links to achieve desired length. Ends are usually connected by a pin link which has a removable side plate, called a master link.
a high rpm hand held grinder using small grinding stones or burrs for metal removal in cramped or hard to get at areas.
a circular disc with a portion removed. It covers and uncovers intake port of two-stroke cycle engine. Disc is keyed to crankshaft.
rotor oil pump
an oil pump that uses an inner and outer rotor to move oil.
out-of-round condition of a rotating part.
inertia-caused movement of gases through cylinder and exhaust system of a two-stroke cycle or four-stroke cycle engine.
a diagram representing an electrical system.
dual-purpose piston ring that helps seal combustion pressure as well as control oil.
secondary ignition circuit
part of ignition systems consisting of secondary winding of ignition coil, spark plug wire, spark plug terminal, and spark plug.
thousands of turns of fine wire in an ignition coil. It uses induction to step up voltage as a magnetic field is rapidly collapsed in primary windings.
a cup located at bottom of fuel petcock designed to prevent flow of dirt and water into fuel line.
a device that converts AC to DC through use of selenium plates.
a circuit in which current must follow a single path through each component in sequence before reaching ground. If one component fails, entire circuit is open.
use of a drive shaft, universal joints and gears to connect gearbox output shaft to rear wheel.
a drum shaped gearbox component with slots around its outside diameter. It engages with shift mechanism and shift forks. As drum is rotated, drum slots cause shift forks to move sliding gears or dogs causing engagement and disengagement of various gearbox ratios.
a flat forked gearbox component that engages with a slot in a sliding gear or dog. Shifting forks slide back and forth on lateral shafts. Rotation of shift drum or cam plate causes shift fork to move its sliding gear or dog to engage with another gear, locking both gears to shaft.
hinged lever or levers that transfer movement of shift lever to shift drum or cam plate.
a fork or pin that limits movement of shift drum to prevent overshifting.
a spacer used between two parts to achieve proper clearance.
a cylindrical shaped part in DOHC (double overhead camshaft) valve train. It is located between valve and camshaft and provides a receptacle for valve lash adjustment shims.
rear suspension unit made up of a coil spring and a hydraulic damper. It prevents spring oscillations. See also power transmission shock absorber.
crankshaft configuration where two rods are mounted on same crank pin (journal). One rod is forked the other is mounted on inside of fork.
crankshaft configuration where connecting rods are mounted next to each other on same crankpin (journal).
a graphical representation of 360 degrees of rotation, representing change in direction of single-phase AC.
a drum brake having two shoes: one is leading and one is trailing. Leading shoe tends to wedge itself into drum providing more braking action than trailing shoe.
alternating current that reverses direction of flow every 180 degrees.
a laterally floating disc brake caliper that uses one hydraulic piston to apply both brake pads. As pressure is applied to piston, it pushes one pad against disc. Other pad is solidly mounted on opposite side of caliper and makes contact with disc as caliper floats.
a conventional roller chain with one row of rollers.
a carburetor mounted on an aluminum manifold by a pinch bolt that clamps carburetor spigot over a plastic or fibre- insulating sleeve.
a carburetor using a throttle slide (plunger) to regulate venturi restriction (throttle opening).
slide cutaway circuit
carburetor circuit which controls air-fuel ratio from one-eighth to one-quarter throttle opening. Height of cutaway portion of slide controls how much air is mixed with fuel. Fuel is metered by pilot jet, needle jet and jet needle.
sliding gear (dog gear)
a gear splined to its shaft and moved side to side by a shifting fork. A sliding gear has dogs on its lateral face that engage with holes or dogs in adjacent gears.
SOHC (single overhead camshaft)
a single overhead camshaft located in top of cylinder head.
solid roller chain
roller chain using a one-piece roller and bushing assembly.
a carburetor mounted by clamping spigot into a rubber sleeve manifold.
spindle (steering fork)
a shaft that is secured to upper and lower triple clamps. It pivots on bearings mounted in steering head.
number of spokes crossed on same side of hub by any one spoke.
a wheel consisting of a rim, spokes, nipples and hub. Spokes are laced between hub and rim and are attached to rim by nipples. Thirty-six or forty spokes are termly used.
spoke torque wrench
a small torque wrench used to accurately adjust spoke tension.
static installed length of a spring subtracted from its free length. In suspension system, spring preload determines ride height of motorcycle.
a device that measures spring pressure in relation to spring length.
a circular plate with teeth machined around outside to engage links of a chain.
a frame stamped from pieces of sheet metal that are welded together to provide support for engine and suspension.
a wheel assembly using stamped sheet metal spokes in place of small wire type spokes. A stamped wheel resembles a cast alloy wheel in appearance.
backward flow of air-fuel mixture in intake tract caused by radical port or cam timing.
carburetor system that provides a rich mixture for cold starting (tickler, choke, enrichment circuit). Also, electrical circuit for cranking engine, including: starter switch, relay, battery, and starting motor.
static ignition timing
use of a buzz box, test light or ohmmeter to check ignition timing without running engine.
a device that uses friction or a hydraulic damper to reduce steering oscillation.
forward part of frame providing a mounting place for bearings that locate and support steering spindle and fork assembly.
distance between steering axis and axis on which axle pivots. Steering offset is accomplished by offsetting axle or triple clamps.
angle of steering axis from vertical, given in degrees.
distance along ground between lines drawn vertically through front axle and down centre of fork tubes and sliders.
straight-cut gear drive
a gear drive which uses gears having straight-cut teeth, used for one type of primary drive.
straight-cut offset gear
a gear design using straight-cut gears installed side-by-side and one-half tooth out of phase. This gear design will eliminate noise caused by backlash common to conventional straight-cut gears.
movement of piston from TDC to BDC or from BDC to TDC.
lowest position of crankcase, containing oil.
a block of granite ground and lapped to provide a very smooth, flat surface. It is used for checking straightness of cylinders, cylinder heads, and crankcase joints.
components that absorb road surface irregularities to smooth motorcycle ride. It is designed to permit controlled wheel movement over irregular surfaces. Basic parts include forks, swing arm and shock absorbers.
main member of rear suspension that provides a mounting place for rear wheel and one end of shock absorbers.
swing arm pivot
forward part of swing arm, where it is attached to frame and pivots on bushings or bearings.
two sides or events being identical. For instance, two-stroke exhaust timing is symmetrical. Exhaust port opens and closes at same crankshaft position before and after TDC.
a wheel hub (wire wheel) that has spoke holes on each side of hub at same distance from hub center.
adjustment of carburetor throttles on two or more carburetors, so that all throttles are open same amount at any position of throttle twist grip.
a small diameter at one end of part, for instance: tapered piston or taper cylinder bore.
front suspension unit made up of two fork tubes and two sliders that telescope up and down tubes against spring pressure.
a "T" shaped instrument used to duplicate distance between inside parallel surfaces (cylinder bore for example).
a temperature sensitive device used in a liquid cooling system to adjust flow of coolant as coolant temperature changes.
alternating current with a 120-degree phase difference. Three wires are needed to carry current.
a cable consisting of an outer housing and an inner cable that connects carburetor to throttle twist grip.
throttle stop screw
an idle speed adjustment screw used in slide type carburetor. This screw contacts base of throttle slide. As screw is turned in, throttle slide is raised, increasing idle speed.
throttle twist grip
a device mounted on end of handlebar that locates one end of outer throttle cable and pulls inner cable as twist grip is rotated.
a washer used to bear side thrust loads or provide lateral location.
a spring-loaded plunger in carburetor that can be depressed to push float assembly down. This allows fuel to flow into float bowl, raising float level temporarily for cold starting.
tire pressure gauge
a pressure gauge used to check tire air pressure.
top dead center (TDC)
uppermost piston travel in cylinder.
part of an engine from cylinder base up, including pistons but not connecting rods.
a twisting force measured in foot-pounds or newton-metres.
a fluid turbine that takes place of clutch in primary drive. Oil is used to transmit power through torque converter depending upon engine rpm. Used in automatic transmissions.
a specific sequence of tightening fasteners to help prevent warping of components.
a wrench calibrated to allow for accurate application of tightening force to fasteners.
opening in cylinder wall of a two-stroke cycle engine that connects cylinder to crankcase.
transfer (port) timing
amount of time transfer port is open, expressed in crankcase degrees or piston position.
a pair of sturdy brackets that provide a mounting place for fork legs and steering spindle. Triple clamps attach forks to frame through spindle, steering head and steering head bearings.
a chain having three rows of rollers. Triplex chains are used for primary drives.
a cycle of overlapping events (intake, transfer, compression, power, exhaust) which all occur during one revolution of crankcase.
engine design has one crankcase to house gearbox, clutch, primary drive, and engine.
a flexible joint that allows changes in angle of drive shaft.
pressure that is less than atmospheric pressure.
a carburetor using a butterfly to regulate airflow and a vacuum controlled piston to regulate venturi restriction.
a gauge that measures pressures which are lower than 14.7 lb. per square inch (101 kPa) at sea level.
throttle piston used in a vacuum operated CV carburetor. One type uses a diaphragm at top with a small diameter piston. Other type uses a large diameter piston in a vacuum cylinder.
a device that controls flow by opening and closing. For instance, fuel valve controls flow of fuel from fuel tank to carburetor. Intake valve controls flow of air-fuel mixture into cylinder.
period of time when intake and exhaust valves in a four-stroke cycle engine are open at same time.
portion of valve that slides in valve guide and provides a mounting place for valve spring upper collar and keepers.
all components which directly influence valve operation (cam, cam chain, cam followers, valves, valve springs, valve collars, and keepers in SOHC engine).
a build-up of oxidized oil or fuel.
cylinders positioned at angles to each other forming a "V".
a tube or drillway going from top of float chamber to atmosphere. This prevents build-up of pressure or vacuum in float chamber.
a restriction in a tube that cause an increase in air velocity, resulting in decrease of pressure (increase in vacuum) at restriction.
a precision measuring tool used to determine inside, outside, or depth measurements. A linear vernier scale is used.
a machine tool that removes metal with a rotating cutter mounted vertically.
the resistance that oil offers to flow when it is subjected to stress (thickness or weight).
force causing electron flow in conductor.
an instrument that measures electrical pressure (EMF, voltage) in electrical circuits.
unit of measurement of electrical power (rate of doing work).
minimum and maximum acceptable size of a component.
use of heat to fuse two pieces of metal together.
a multi-plate clutch that runs in an oil bath (primary drive).
four-stroke cycle engine sump (crankcase) in oil reservoir.
wheel bearing grease
a special, heavy duty, high temperature grease used to lubricate wheel bearings.
wide ratio gearbox
a gearbox having wide ratio spacing between gears. A wide ratio gearbox is commonly used in enduro (off-road) and trials motorcycles.
a measuring tool made of precisely sized wire. It is for measuring distance between irregular surfaces (spark plug gap for example).
see spoked wheel.
parallel-sided piece inserted into groove cut part way into each of two parts, which locates and prevents slippage between parts.
a solid-state device used to regulate voltage in motorcycle charging systems.
(İng. Anti-lock Brake System , Alm. “Anti Blockier Sytem” - Wabco Gmbh tarafından patentli)Kilitlenme önleyici fren sistemi. Sistem, yol şartlarına göre kilitlenmeyi hissedip, bilgisayarda değerlendirmekte ve durma süresince birden cok kez freni açıp kapayarak kilitlenmeyi önlemektedir
Motosikletlerle grup sürüşü sırasında en arkadan gelen motosiklete verilen genel isim
(Fr.Alternateur , İng.Alternator) Motor çalışırken ürettiği doğru akım (DC) ile elektrik sistemini besleyen güç üretim ünitesi.
(İng.Anti freeze) Soğutma suyunun donmasını engellemek için radyatöre konulan , %50’si glisol , %50’si su olan bir sıvıdır.
Ateşleme avansı olarak da bilinir. Silindir içinde sıkıştırılan yakıt hava karışımının tamamen yanabilmesi için gereken süredir.
Genellikle kış kullanımı için, bazen sadece gözleri, bazen de tüm yüzü açık bırakan , kafaya geçirilen bir nevi bere.
BMW motosikletlere verilen , yerleşik argo bir tanımlama.
Beygir Gücü (BG)
(İng.Brake Horse Power) 75 Kg’lık bir ağırlığı
(ing.)İlk kez Ferdinand Porsche tarafindan tasarlanan , iki pistonun 180 derece acıyla yere paralel ve birbirlerine karşı çalıştığı motor sistemi. Piston kollarını birbirlerine karşı çalıştığı için boksör hareketine benzetilerek bu isim verilmiştir. BMW R serisi motosikletlerde bu tip motor kullanılmaktadır. (Flat Twin de denir)
(Fr.Bougie , İng. Spark Plug) Ateşleme ünitesi. Porselen bir yalıtkanın içine yerleştirilmiş bakır bir çubuk ve bunun ucunda + ve – kutupları temsilen aralığı genellikle 1-
(Fr.Bobine) Akü voltajını bujide atlama yapıp kıvılcım oluşturabilecek seviyede yükselten ( 15.000 – 25.000 Volt , düşük amper) araçtır.
(İng.) Gidonun dönülmesi gereken virajın yönünün tersine çevrilmesi işlemine verilen ad. Solu it sola dön , sağı it sağa dön tekniği. (Detaylı eğitimi almadan denemeyin)
(İng.) Sipariş üzerine özel üretilmiş , veya zevkinize göre kendinizin kişiselleştirdiğiniz her tip motora verilen ad. (Custom XT200 , custom CBR900RR gibi..)
(İng.) Fabrika üretimi tüm gezinti motorlarına verilen ad. Yere yakındırlar. Sürat ve viraj almak için uygun değildirlerdir. Seri olarak üretilmiş tüm Harley Davidson’lar , Honda Shadow-Magna , Kawasaki Vulcan-EN serileri vs. bu gruba girerler)
(İng.) Tam kelime karşılığı helikopterden gelmedir. Seslerinin benzemesinden çağrışım yapılmış olabilir.Ön çatal açısı (rake) geniş olan cruiser tipi özel üretim motorlara verilen isimdir. Seri olarak üretilmezler. webmaster dan not: helikopterler havayı kestikleri için chopper diye anılırlar. Genelde cruiser tipi motosikletlerin kesilip biçilerek yada tamamen elde yapanın kendi tasarımı olarak ama yine kesip biçilerek yapılmasından kaynaklanan bir terimdir.
(İt.Giunta , İng.Gasket) Sızdırmazlığı sağlayan , genellikle ısıya dayanıklı kauçuk , kösele veya kurşun gibi malzemelerden yapılmış ince parçalara verilen genel ad. (Örnek: Silindir bloğu ile silindir kapağı araındaki sızdırmazlığı sağlayan silindir contası)
(İng. Double Over Head Camshaft) Çok supaplı (silindir başına 4 ve fazlası) motorlarda motor üstünde bulunan supap açma kapamaya yarayan çift kamın kısaltılmış hali.
Otomobillerde bulunan sistem gibi , daha çok yüksek torklu motosikletlerde motor hareketi ile dişli kutusunu ayıran kuru(yağsız) debriyaj sistemidir.
Şanzıman yağının içinde bulunan birçok kavramadan oluşur. Kavramaların arasında yağ bulunur. Daha çok yüksek devirli spor motosikletlerde kullanılır (soğutma amaçlı)
Motosiklet motorunda özel bir supap kontrol sistemi. Geleneksel yay ile geri çekme yerine ilk kez Mercedes tarafından kullanılmış ve şimdi Ducati motosikletlerinde gelenekselleşmiş bir sistemdir. Daha yüksek devir ve beygir gücüne imkan tanır
Özel bir yariş türü olan çamurlu pistlerde yarışmak amacı ile üretilmiş motokros tipi motosikletlere verilen ad
Frenlemenin fren balatası – kaliperler ve çelik disk üçlüsü ile sağlandığı sistem.
(İng. Department of Transportation) Ulaşım departmanın belirlediği standartları imleyen kısaltma.
Pistonun her devrinde 4 işlem yapılır. 1.zaman:Hava veya yakıt hava karışımını emme 2. Sıkıştırma, 3. Ateşleme/Patlama (Kimyasal enerjinin mekanik enerjiye dönüştüğü nokta 3.Egzozdan atma.
(İng.) Hem iyi yol hem de kötü yol koşullarına cevap verebilecek nitelikteki motosikletlere verilen ad.
(Fr. Distributeur) Motorun ateşleme sırasına göre bujilere akım dağıtan araç.
Meşhur motosiklet filmi.(1969, Peter Fonda, Dennis Hopper, Jack Nicholson)
(İng. exhaust) Motorlu tasitlarda yanan gaz veya bunun duzenegi (Yanlış kullanım : eksoz, egzos , egsoz , ekzost.....)
(İng. Endurance) Kelime anlamı dayanıklılıktan gelen bu terim hızdan çok zamana karşı belli tecrübe ve yeteneklerin ön plana çıktığı yarışlara verilen genel addır
(İng.) Motokros motosikletinden farklı olarak daha aralıklı vites oranları ve 650cc’ye kadar da motor hacimleri olabilir. Daha hızlı olmakla birlikte motokross motosikletlerinden daha ağır olurlar.
Tek bir pedal veya kola fren uygulandığında işlemci veya mekanik dağılım ile ön-arka tekerleklere giden hidrolik basıncını ayarlayarak motosikletin en kısa/güvenli şekilde durmasını sağlayan fren sistemi.
(İng.) İki pistonun 180 derece acıyla yere paralel ve birbirlerine karşı çalıştığı motor sistemi.(Bknz.Bokser)
(İng.) Çenesi açılıp kapanmayan , yarım olmayan ve kafanın tamamını koruyan kask tipine verilen ad. En iyi korumayı sağlayan kask tipidir. Kullanımı nispeten biraz daha zordur.
(fr.guidon) Motosikleti yönlendirmeye yarayan tutamaç.Yönelteç (Yanlış kullanım : didon)
Ani bir çukura girildiğinde ön tekerleğin motosikletin yol çizgisinden ani sapmasını engellemek için insan gücünün karşılayamayacağı büyüklükteki yükü absorbe etmek için kullanılan düzenek. Genellikle yarış motosikletlerinde kullanılırlar.
(İng. Global Positioning System) Küresel konumlama sistemi. Dünya yörüngesindeki yaklaşık 24 uydudan gelen sinyalleri analiz ederek noktasal hassasiyette konumunuzu belirlemeye yarayan sistem. Uygun donanımlı ve yazılımlı bir GPS aleti ile yol tarifi alabilir , gittiğiniz yerleri hafızaya kaydedebilirsiniz.
Motorun emme manifolduna giden havayı temizlemeye yarayan süzgeç/filtre.
Heel – Toe Shifter
(İng.) Motosikletteki klasik vites değiştirme sistemine eklanan bir parça ile ayağınızı koyduğunuz bir plaka vasitası ile topuk kısmına bastırdığınızda vitesi büyüten , burun kısmına bastırdığınızda ise vitesi küçülten bir sistemdir. Genellikle Cruiser tipi motorlarda görülür
(İng.) Sürücünün motosikletin gidonunun üzerinden uçtuğu durumlar için kullanılan terim. Genellikle arka frenle yapılan ağır frenlemelerde motosikletin arkası yalpalarken sürücünün freni bırakması sonucu boşalan yükün tepkisi sonucu sürücüyü üzerinden fırlatması durumu.
(İng. Harley Owners Group) Harley sahipleri grubu. Dünyaya yayılmış yaklaşık bir milyon üyesi olan , 1983’de kurulmuş bir kulüptür
(İng.) Tam türkçeye çevirmek yerine neyi ifade ettiğini söylemek daha iyi olacaktır. 1 günde
(fr.gic lée) Emme manifolduna giden havayı kısarak karışımın zengin (yakıt ağırlıklı) olmasını sağlayan düzenek. Bazı motosikletlerde elle , bazılarında otomatiktir. Özellikle soğuk havalarda ilk çalıştırmada kullanılır. (Zenginleştirici – enrichener olarak da kullanılır) (Yanlış kullanım : cikle)
(İng.) Şarjı bitmiş bir akünün çalışır durumdaki bir aracın iyi durumdaki bir aküsünden paralel kablolarla şarj/diğer aracı çalıştırma yöntemidir.
Lastiklerin takildigi tekerlegin cember bicimindeki bolumu,ispit (fr.jante) (Yanlış kullanım : Cant)
Frenlemenin fren balatası – yay - güç kolu ve çelik tas ile sağlandığı sistem. Genelde eski motorlarda ve günümüzde de bazı motosikletlerin arka tekerleklerinde kullanılır.
Disk frenlerin, balataları da içeren ve disklerin hidrolik oalrak sıkılmasına yarayan kısmı.
(fr.Carburateur) Patlamalı motorlarda yakıt ile havayı karıştıran düzenek
Motosikletin sasisini orten bir nevi karoser (Yanlış kullanım : Grenaj)
(fr.casque) Kullanıcının başını ciddi yaralanmalardan korumak için giydiği koruyucu başlık
(İng.) Günümüzde yaygın olarak kullanılmamakla birlikte Motocross , Scooter , Commuter tipi motorlarin bazilarinda elektrikli marşla birlikte veya tek başına sunulan , bir pedala aşağı doğru bir kuvvet uygulanarak motorun başlangıç hareketinin sağlanması sonucu motorun çalışmasına yardımcı olan düzenek.
(İng.) Motorun ateşleme düzeneğine giden elektriği kesmeye yarayan düğme. Özellikle kaza anında ilk yapılması gerekenlerden biri motora giden ateşlemeyi keserek olası bir yangını engellemektir.
Voltaj Ayarlayacı. Alternatörün ürettiği yüksek voltajlı elektriği tüm elektrik sistemini besleyebilecek seviyede sabit tutmaya yarayan regülatör.
Motorun alt kısmını muhafaza eden parça.
Egzoz gazında bulunan zararlı CO veya HC bileşiklerini yakarak daha az zararlı gazlara çeviren , 1974 yılında buluşu yapılmış , gaz emisyonunu düşüren bir parçadır.
(İng.) Motosikletin ve sürücünün yere düştüğü durum. Bazen motosiklet sürücüleri bilinçli olarak motosikletlerini bırakarak/kaydırarak düşerler , ancak bu durum bazen daha fazla hasar ve yaralanmalara yol açabilir.
(İng. Light Emitting Diode) Işık saçan diyot. Klasik ampüllere göre elektrik akımına daha hızlı tepki verdiklerinden dolayı ikaz ışıklarında (sinyal , stop lambası gibi) kullanılmaya başlanmıştır.
Katalitik Konvertör’ün önüne yerleştirilen , egzoz gazındaki O2 miktarını ölçen aygıttır. Sensör karışımdaki O2 miktarını mV olarak hesaplayıp değeri kumanda merkezine (beyin) ileterek en uygun karışımın hazırlanmasını sağlar.
(fr.)Pedaldan yardım alarak çalışan max.50 cc’lik motorlu bisiklet.
(ing. Motocross) Genellikle insan yapımı tepeler ve dönüşlerle dolu , toprak-çamur karışımı pistlerin olduğu ve “Moto” adı verilen (Bizde bilinen adı ile Motokros motoru , dağ motosikleti) motorlarla yapılan yarışma
Yerden yüksek , yüksek ve yakın vites oranlı (Yüksek hızlanma , düşük üst hız) , fazla ön amortisör yolu olan , özel dişli lastikli , büyük cantli motosikletler. Dağ motosikleti olarak da bilinirler. Genellikle 250 cc’ye kadar olurlar.
Motor Koruma Demiri
Motosiklet motorunu dış darbelerden korumak için şasiden destek almış çelik bir korumadır.
(fr.motocyclette) Motor silindirinin hacmi 125 cm³ den buyuk olan, iki tekerlekli motorlu tasit (yanlış kullanım : MotoRsiklet)
(İng.) Karenajı (rüzgar koruması) olmayan/çok az olan , şasesi açıkca görülebilen spor – spor/turlama motorlarına verilen genel ad. Çıplak motor.
Motosikleitn alt kısmına monte eidlmiş, yaylı mekanizması olan, kullanıldığıdında motosikletin arka lastiğini yerden havada tutan veya motosikleti dengede tutan aparat.
(fr.odomètre) Motosikletin o ana kadar kattetiği mesafeyi mil ya da kilometre cinsinden gösteren ekrana verilen ad.
(İng.)Asfaltlanmış , beton atılmış , düzlenmiş , kısaca işlem görmüş yollar dışındaki yollar. Köy yolları veya stabilize yollar off-road değillerdir.
(İng. Centre Stand) Motosikletin ağırlık merkezine çok yakın konumlandırılmış , motosikletin dengede durması sağlayan (zincir yağlarken , lastik değiştiriken , kışlamalarda) çift ayak.
(Alm.) İlk kez BMW R100GS de kullanılna radikal bir arka süspansiyon sistemidir. Paralelogram prensibi ile çalışan ve bir tork kolu yardımı ile şaftın iki açıda hareketine olanak tanıyan sistem.
Motosikleti kullanirken ayaklarin konulduğu yer , ayaklik (Yanlış kullanım : ped)
(ing.pillion) Motosikletde sürücünün arkasında yolculuk yapan kişi, yolcu.
Motosiklet sürücüsü , sürücü
(ing) Pilot , motosiklet sürücüsü , sürücü
Ride to Work Day
(İng.) 1989 yılında işten eve evden işe t-shirtleri ile ağza dolanan bu etkinlik 1992 ‘den beri düzenli olarak her yıl motosiklet sürücülerinin motosikletleri ile işe gitmesi ile anılır.
(İng. Revolution Per Minute) Motorun bir dakikada yaptığı tur sayısı. Devir/dakika
(Fr.Radiateur) Soğutma sistemi yağ veya su ile olan araçlarda ısınmış sıvıyı peteklerinden geçirirken fan veya aracın hızının oluşturduğu akımdan faydalanarak soğutmaya yarayan araçtır.
(İng.Reflector) Yansıtaç. Kendisine gelen ışığı değişik açılarda yansıtmaya yarayan araç.
(Fr.Ralenti) Gaz kelebeği serbest durumdayken, motorun yüksüz ve boşta çalışma devridir.
(İng. Single Over Head Camshaft) Supaplı (silindir başına 2 veya fazlası) motorlarda motor üstünde bulunan supap açma kapamaya yarayan üstten tek kamın kısaltılmış hali.
(fr. selle) Motosikletin veya bisikletin oturulacak yeri
Piston alt ölü noktada iken hesaplanan silindir içi hacmin , piston üst ölü noktaya geldiğinde hesaplanan hacime oranıdır.Dizel motorlarda sıkıştırma oranı benzinlilere göre daha yüksektir.
(İng.) Genellikle cruiser tipi motorlarda pilyon (yolcu) nun yaslanabileceği arkalık.
(İng.)Ortada ayak koyma yeri olan -veya ortada deposu olmayip , sadece şase geçişi olan – küçük motosiklet.(Piaggio Vespa türün ilk örneklerindendir.)
(İng.)Pistlerde yarışmak amacı ile üretilmiş hız motosikletlerinin genel adı ( Honda CBR 1000RR , Kawasaki ZX10R , Yamaha R1..)
(İng.) Spor bir motosiklet gibi sportif motora sahip olan , ancak turlama motorlarındaki gibi konfor içeren motosiklet ( Honda PAN European ST1300, Yamaha FJR 1300 , BMW K1200GT...)
(İng.)Ön frenlerin ayarlı bir şekilde sıkılması ile ön teker dengeli bir biçimde duruken arka tekerleğin havalanmasına verilen ad(Dikkat , sadece profesyoneller yapabilir ve tehlikelidir)
(fr.soupape) Valf olarak da bilinir. 4 zamanlı motorlarda silindirlerin üzerinde , iki zamanlılarda yanlarında buluna giriş ve çıkış kanallarının kapakları. 4 zamanlı motorlarda biri emme , biri ekzoz olmak üzere en az 2 adet bulunmaktadır.(Yanlış kullanım : Sibop , sübap vs..)
(İng.) Motocross yarışmalarının kapalı alanlarda ve görece daha kısa parkurlarda yapılan hali.
(İng.) Salıncak. Motosikletin şasesi ile arka tekerleğin bribirinden bağımsız hareket etmesine olanak tanıyan parça.
Sentetik Motor Yağı
Petrol bazlı mineral yağların aksine kimyasal reaksiyonlarla ortaya çıkarılmış ileri teknoloji ürünü performanslı motor yağlarına verilen genel ad.
(İng.) Mıknatıs ve/veya kayışlar aracılığı ile depo üstüne yerleştirilebilen fermuarlı çanta
(İng.) Gidonun ani ve yoğun dengesiz salınım hareketi. Genellikle tümsekli bir viraj çıkışındaki güçlü hızlanmalar sırasında görülür. Gidon amortisörleri ile bu hareket kontol altına alınabilir.
(İng.) Hedefe sabitlenme. Motosiklet sürücüsünün yol veya yol dışında bir noktaya (nesneye) odaklanması ve bu noktaya (nesneye) doğru sürüş yönünün kilitlenmesi sonucu sürüş çizgisinin bozulması. “Nereye bakarsan oraya gidersin!”
(İng.) Motosikletin –genellikle- bir otomobile yandan vurmuş haline verilen ad.
(İng. Tachometer) Motorun dakikadaki devrini gösteren ekran/gösterge.
(Alm.) BMW tarafından kullanılan ön amortisör sistemi. Öndeki iki çatalın içi yağ ile doluyken iki dirsek noktası ile salıncak görevi gören bir mekanizma vardır. Bunun sayesinde motosiklet ağır frenlemelerde ve çukurlarda ön tarafa dalma yapmaz.
(fr.Torques) Bir nesnenin ekseninden belirli mesafede uygulanan döndürme kuvvetine verilen addır. Örneğin bir somunu anahtarla açmaya çalışan bir operatör eğer 20 kgf’lık bir kuvvet uygulyor ise ve anahtar yük boyu
(İng.) Arkası iki tekerlekli olan üç tekerli motosikletlere verilen genel ad. Motosiklet şasesi üzerine kurulur ve arka tekerlek sökülerek yerine otomobil dingili ve özel bir şanzıman konulur.
(İng.) Turlama motosikleti. Her ne kadar her motosiklet
(İng.) Şambrelsiz (iç lastik) lastik anlamında kullanılır.(Yanlış kullanım : Dubleks)
(İng.) İki egzoz çıkışının olduğu silindir kafasına verilen ad.
(İng.Valve) Bakınız Supap.
(İng.) Konumlanması V şeklinde ve belli bir açıda olan (45 , 55 , 60 vs..) motorlara verilen ad.
(Fr. Viscosité) Akıcılık derecesi.Belli yoğunluk ve hacimdeki sıvının belli bir çaptan akma zamanı ile ölçülür. Numaralar düştükçe akıcılık artar (Su düşük , bal yüksek viskosdur)
Detenasyon da denir. Yakıt hava karışımının bujinin ateşlemsinden önce kendi kendine tutşmasından doğan düzensiz ateşlenmedir. Bunun sonucunda motorun verimi düşer ve vuruntu denilen sesler duyulur.
(İng.) Gazın (debriyaj yardımı ile de olabilir) belirli bir güçte kullanılması ile ön tekerleğin yerden kesilmesine verilen ad. Tekteker.
Pistonun her bir devrinde iki işlem yapmaktadır. Piston yukarı hareketinde sıkıştırma ve patlama, aşağı hareketinde ise yakıt hava karışımın emme ve egzozu dışarı atma.
Motorun yağını filtreden geçiren düzenek. Her motosiklet sürücüsü manuelde belirtilen periyodlarda yağ değişimi ile bu filtreyi değiştirmelidir. Aksi halde filtrede biriken metal parçacıklar motora hasar verebilir.
Motosiklet park pozisyonundayken soluna belli açıda yatmasını sağlayan yardımcı çubuk. Günümüzde birçok motosiklet yan ayak açıkken ya çalışmaz ya da vitese atıldığı anda durur.
(İng.Saddlebags) Motorun arkasında her iki yana sarkan ve tutturulan sert malzeme(Plastik , aliminyum , fiber vs) veya deriden yapılmış çantalar
Motosikletde sürücünün arkasında yolculuk yapan kişi. Bknz. Pilyon
(İng. Enrichener) Bknz. Jikle
Motor gücünün arka tekerleğe bir zincirle aktarılması turlama için kullanılabilse de , genel anlam olarak az bakım gerektiren , çantalı , büyük yakıt tankı ve rüzgar koruması olan motosikletlere verilen genel ad.