Glossary (2) - Polaris Magnum 2x4 Service Manual

GENERAL INFORMATION
Glossary Of Terms
ABOC:
After bottom dead center.
ACV:
Alternating current voltage.
Alternator: Electrical generator producing voltage alternating current.
ATDC:
After top dead center.
BBDC: Before bottom dead center.
BDC: Bottom dead center.
BTOC: Before top dead center.
CC:
Cubic centimeters.
COl: Capacitor discharge ignition. Ignition system which stores voltage generated by the stator plate exciter coil in a
capacitor or condenser (in COl box). At the proper moment a voltage generated by the stator plate pulser coil closes an
electronic switch (thyristor) in the COl box and allows the voltage in the capacitor to discharge into the primary windings
of the ignition coil.
Center Distance: Distance between center of crankshaft and center of driven clutch shaft.
Chain Pitch: Distance between chain link pins (No. 35
=
3/8" or 1 cm). Polaris measures chain length in number of
pitches.
CI: Cubic inches.
Clutch Buttons: Plastic bushings which transmit rotation of the clutch to the movable sheave in the drive and driven
clutch.
Clutch Offset: Drive and driven clutches are offset so that drive belt will stay nearly straight as it moves along the clutch
face.
Clutch Weights: Three levers in the drive clutch which relative to their weight, profile and engine RPM cause the drive
clutch to close.
Condenser/Capacitor: A storage reservoir for electricity, used in both E.T. and COl systems.
Crankshaft Run-Out: Run-out or "bend" at crankshaft measured with a dial indicator while crankshaft is supported
between centers on V blocks or resting in lower half of crankcase. Measure at various pOints especially at PTO.
Maximum allowable run-out is .006" (.02 cm).
Dev:
Direct current voltage.
Detonation: The spontaneous ignition of the unburned fuel/air mixture after normal spark ignition. Piston looks
"hammered" through, rough appearance around hole. Possible causes: 1) too high a compression ratio for the fuel
octane; 2) low octane fuel; 3) over-advanced ignition timing.
Dial Bore Gauge: A cylinder measuring instrument which uses a dial indicator. Good for showing taper and
out-at-round in the cylinder bore.
Electrical Open: Open circuit. An electrical circuit which isn't complete. (i.e. poor connections or broken wire at hi-Io
beam switch resulting in loss of headlights.
Electrical Short: Short circuit. An electrical circuit which is completed before the current reaches the intended
component. (i.e. a bare wire touching the snowmobile chassis under the seat resulting in loss of taillights and brake
lights).
End Seals: Rubber seals at each end of the crankshaft.
Engagement RPM: Engine RPM at which the drive clutch engages to make contact with the drive belt.
ft.:
Foot/feet.
Foot Pound: Ft. lb. A force of one pound at the end of a lever one foot in length, applied in a rotational direction.
g: Gram. Unit of weight in the metric system.
gal.: Gallon.
Head Volume: Cylinder head capacity in cc, head removed from engine with spark plug installed.
High Tension Lead: The heavy insulated wire which carries the high secondary voltage from the coil to the spark plug.
Holed Piston: Piston in which a hole has formed on the dome. Possible causes: 1) detonation; 2) pre-ignition.
HP: Horsepower.
10: Inside diameter.
Ignition Coil: A type of transformer which increases voltage in the primary windings (approx. 200V) to a higher voltage
in the secondary windings (approx. 14KV - 32KV) through inductions. Secondary voltage is high enough to arc the air
gap at the spark plug.
Ignition Generating Coil: Exciter coil, primary charge coil. Stator plate coil which generates primary ignition voltage.
in.: Inch/inches.
Inch Pound: In. lb. 12 in. Ibs.
=
1 ft. lb.
7/96
1.28
Polaris Industries Inc.