Angle-tightening cylinder head bolts

AntifreezeA substance (usually ethylene glycol)

mixed with water, and added to the cooling

system, to prevent freezing of the coolant in

winter. Antifreeze also contains chemicals to

inhibit corrosion and the formation of rust and

other deposits that would tend to clog the

radiator and coolant passages and reduce

cooling efficiency.

Anti-diveSystem attached to the fork lower leg

(slider) to prevent fork dive when braking hard.

Anti-seize compoundA coating that reduces

the risk of seizing on fasteners that are subjected

to high temperatures, such as exhaust clamp

bolts and nuts.

APIAmerican Petroleum Institute. A quality

standard for 4-stroke motor oils.

AsbestosA natural fibrous mineral with great

heat resistance, commonly used In the

composition of brake friction materials. Asbestos

is a health hazard and the dust created by brake

systems should never be inhaled or ingested.

ATFAutomatic Transmission Fluid. Often used

in front forks.

ATUAutomatic Timing Unit. Mechanical device

for advancing the ignition timing on early

engines.

ATVAll Terrain Vehicle. Often called a Quad.

Axial playSide-to-side movement.

AxleA shaft on which a wheel revolves. Also

known as a spindle.

B

BacklashThe amount of movement between meshed components when one component is held still. Usually applies to gear teeth. Ball bearingA bearing consisting of a hardened inner and outer race with hardened steel balls between the two races.

BearingsUsed between two working surfaces to prevent wear of the components and a build­up of heat. Four types of bearing are commonly used on motorcycles: plain shell bearings, ball bearings, tapered roller bearings and needle roller bearings.

Bevel gearsUsed to turn the drive through 90°. Typical applications are shaft final drive and camshaft drive (see illustration).

Bevel gears are used to turn the drivethrough 90°

BHPBrake Horsepower. The British

measurement for engine power output. Power

output is now usually expressed in kilowatts

(kW).

Bias-belted tyreSimilar construction to radial

tyre, but with outer belt running at an angle to the

wheel rim.

Big-end bearingThe bearing in the end of the

connecting rod that's attached to the crankshaft.

BleedingThe process of removing air from an

hydraulic system via a bleed nipple or bleed

screw.

Bottom-endA description of an engine's

crankcase components and all components

contained there-in.

BTDCBefore Top Dead Centre in terms of piston

position. Ignition timing Is often expressed in terms

of degrees or millimetres BTDC.

BushA cylindrical metal or rubber component

used between two moving parts.

BurrRough edge left on a component after

machining or as a result of excessive wear.

c

Cam chainThe chain which takes drive from the

crankshaft to the camshaft(s).

CanisterThe main component in an evaporative

emission control system (California market only);

contains activated charcoal granules to trap

vapours from the fuel system rather than allowing

them to vent to the atmosphere.

CastellatedResembling the parapets along the

top of a castle wall. For example, a castellated

wheel axle or spindle nut.

Catalytic converterA device in the exhaust

system of some machines which converts certain

pollutants in the exhaust gases into less harmful

substances.

Charging systemDescription of the

components which charge the battery, ie the

alternator, rectifer and regulator.

Circlip Aring-shaped clip used to prevent

endwise movement of cylindrical parts and

shafts. An internal circlip is installed in a groove

in a housing; an external circlip fits into a groove

on the outside of a cylindrical

piece such as a shaft. Also known as a snap-ring.

ClearanceThe amount of space between two

parts. For example, between a piston and a

cylinder, between a bearing and a journal, etc.

Coil springA spiral of elastic steel found in

various sizes throughout a vehicle, for example

as a springing medium in the suspension and in

the valve train.

CompressionReduction in volume, and

increase in pressure and temperature, of a gas,

caused by squeezing it into a smaller space.

Compression dampingControls the speed the

suspension compresses when hitting a bump.

Compression ratioThe relationship between

cylinder volume when the piston is at top dead

centre and cylinder volume when the piston is at

bottom dead centre.

ContinuityThe uninterrupted path in the flow of

electricity. Little or no measurable resistance.

Continuity testerSelf-powered bleeper or test

light which indicates continuity.

CpCandlepower. Bulb rating commonly found

on US motorcycles.

Crosspiy tyreTyre plies arranged ina

criss-cross pattern. Usually four or six plies used,

hence 4PR or 6PR in tyre size codes.

Cush driveRubber damper segments

fitted between the rear wheel and final drive

sprocket to absorb transmission shocks (see

Illustration)

Date: 2016-01-14; view: 784