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A measure of movement between meshed gears when one of them is held still (i.e. cam gear teeth). ¹⁾

Device or material placed inside mufflers in order to reduce the sound volume.

A motorcycle with frame mounted hard saddlebags. Normally refers to larger motorcycles but applies to all motorcycles with frame mounted hard saddlebags.

See Sportster Bagger.

An assemble consisting of a hardened inner and outer race with hardened steel balls between the races.

Slang for cylinders.

Usually refined crude oil fraction or selected synthetic base stock. Additives are mixed to them during lubricant manufacturing²⁾.

A device consisting of two or more electrochemical cells in one container that convert stored chemical energy into electrical energy. Motor vehicle batteries are classified as 'secondary' (re-chargeable) batteries. The most common in Harley motorcycles are gel cell (dry cell) batteries due to their aggressive shaking engines. Lead acid (wet cell) uses liquid electrolites in sealed and unsealed containers.

ignition_system_battery_ignition

Bottom dead center - The position of a piston when it is at the lowest point of its stroke.

Before top dead center- The position of a piston when it is on the way up but has not reached it's fullest extension to the top of the cylinder.

The area on a tire that contacts the inside rim of a wheel.

A tool used to separate the tire bead from the rim of a wheel

An assembled unit placed between two working surfaces to prevent wear and heat build up. There are 4 types of bearings commonly installed on a motorcycle: Plain shell bearings, tapered roller bearings, needle roller bearings and ball bearings. ³⁾

Bevel gears are used to turn the drive through 90 degrees. Examples include the final drive shaft and the pinion shaft to camshaft gearing. ⁴⁾

(Brake Horsepower): British measurement for engine power output commonly expressed of late in Kilowatts (kW).⁵⁾

It is of similar construction to radial tires but the outer belt runs at an angle to the rim of the wheel.

The bearing at the bottom of the connecting rod that attaches to the crankshaft.

Removing the air from the brake hydraulic system by the use of an air bleeder screw which has a hole in the center for removing the fluid and/ or air when loosened.

Fictitious fluid told to be needed to newby riders whose turn signals don't work.

Newby: Hey my left blinker is not working

Greybeard: Did you check the blinker fluid?

Newby: No, where do I check it at?

The inside diameter of a round hole, commonly noted for the inside diameter of a piston cylinder. Any object that has a round hole in it has a “bore” that can be measured including connecting rods, holes in the case for lifters and shafts etc. Special tools are required to achieve true measurements including a Dial Bore Gauge or Telescoping Bore Gauge which is then measured with a Dial or Digital Caliper.

The position of a piston when it is at the lowest point of its stroke.

Slang for helmet.

Hydraulic powered unit used to house friction pads (brake pads), centered over a wheel mounted brake rotor, to slow down rotation by use of friction as the pads are pushed towards the rotor center.

ignition_system_breakerless

Revving the motor and while holding the front brake in order to make the rear wheel spin and become hot. This produces much smoke as the rubber on the tire burns off.

A circular band of metal that's pressed into a hole to accept a moving part within it's center. Brass is used for cam shafts with a clearanced ID to allow for oiling of the moving part. Bushings have often replaced the use of bearings in certain models.

A rough edge left over after machining a part, or as a result of damage or wear

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