Technical Terms Explained ref

ABS (Anti-lock braking system) A system, usually electronically controlled, that senses Incipient wheel lockup during braking and relieves hydraulic pressure at wheel which is

Aftermarket Components suitable for the motorcycle, but not produced by the motorcycle

Allen key A hexagonal wrench which fits into a recessed hexagonal hole. Alternating current (ac) Current produced by an alternator. Requires converting to direct current by a rectifier for charging purposes. Alternator Converts mechanical energy from the engine into electrical energy to charge the battery and power the electrical system. Ampere (amp) A unit of measurement for the flow of electrical current. Current = Volts Ohms. Ampere-hour (Ah) Measure of battery capacity. Angle-tightening A torque expressed in degrees. Often follows a conventional tightening torque for cylinder head or main bearing fasteners (see illustration).

Angle-tightening cylinder head bolts

Antifreeze A 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

Anti-dive System attached to the fork lower leg (slider) to prevent fork dive when braking hard. Anti-seize compound A coating that reduces the risk of seizing on fasteners that are subjected to high temperatures, such as exhaust clamp

API American Petroleum Institute. A quality standard for 4-stroke motor oils. Asbestos A 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. ATF Automatic Transmission Fluid. Often used

ATU Automatic Timing Unit. Mechanical device for advancing the ignition timing on early

ATV All Terrain Vehicle. Often called a Quad.

Axial play Side-to-slde movement.

Axle A shaft on which a wheel revolves. Also

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

Bearings Used 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

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

BHP Brake Horsepower. The British measurement for engine power output. Power output is now usually expressed in kilowatts

Bias-belted tyre Similar construction to radial tyre, but with outer belt running at an angle to the

Big-end bearing The bearing in the end of the connecting rod that's attached to the crankshaft. Bleeding The process of removing air from an hydraulic system via a bleed nipple or bleed

Bottom-end A description of an engine's crankcase components and all components

BTDC Before Top Dead Centre In terms of piston position. Ignition timing is often expressed in terms of degrees or millimetres BTDC.

Bush A cylindrical metal or rubber component used between two moving parts.

Burr Rough edge left on a component after machining or as a result of excessive wear.

Cam chain The chain which takes drive from the crankshaft to the camshaft(s). Canister The 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. Castellated Resembling the parapets along the top of a castle wall. For example, a castellated

Catalytic converter A device in the exhaust system of some machines which converts certain pollutants In the exhaust gases into less harmful

Charging system Description of the components which charge the battery, ie the alternator, rectifer and regulator. Circlip A ring-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. Clearance The amount of space between two parts. For example, between a piston and a cylinder, between a bearing and a journal, etc. Coil spring A spiral of elastic steel found In various sizes throughout a vehicle, for example as a springing medium in the suspension and in

Compression Reduction in volume, and increase in pressure and temperature, of a gas, caused by squeezing it into a smaller space. Compression damping Controls the speed the suspension compresses when hitting a bump. Compression ratio The relationship between cylinder volume when the piston is at top dead centre and cylinder volume when the piston is at

Continuity The uninterrupted path in the flow of electricity. Little or no measurable resistance. Continuity tester Self-powered bleeper or test light which indicates continuity. Cp Candlepower. Bulb rating commonly found

Crossply tyre Tyre plies arranged in a criss-cross pattern. Usually four or six plies used, hence 4PR or 6PR in tyre size codes. Cush drive Rubber damper segments fitted between the rear wheel and final drive sprocket to absorb transmission shocks (see

Cush drive rubbers dampen out transmission shocks

DIY Battery Repair

DIY Battery Repair

You can now recondition your old batteries at home and bring them back to 100 percent of their working condition. This guide will enable you to revive All NiCd batteries regardless of brand and battery volt. It will give you the required information on how to re-energize and revive your NiCd batteries through the RVD process, charging method and charging guidelines.

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