Spark Plugs; Spark Plug Inspection; Spark Plug Recommendations - Polaris RANGER 400 Owner's Manual

MAINTENANCE

Spark Plugs

Spark Plug Recommendations

Refer to the specifications section beginning on page 86 for the recommended spark plug
type for your vehicle. Always torque spark plugs to specification.
NOTICE: Using non-recommended spark plugs can result in serious engine damage. Always use
POLARIS-recommended spark plugs.
Spark Plug Gap/Torque
Model Electrode Gap New Plug Used Plug
Torque Torque
RANGER 400 .036" (.9 mm) 9-11 ft. lbs. 9-11 ft. lbs.
(12-15 Nm) (12-15 Nm)

Spark Plug Inspection

Spark plug condition is indicative of engine operation. The spark plug firing end condition
should be read after the engine is warmed up and the vehicle is driven at higher speeds.
Immediately check the spark plug for correct color.
CAUTION! A hot exhaust system and engine can cause burns. Wear protective gloves when
removing a spark plug for inspection.
1. Remove the seat to access the engine compartment.
2. Remove the spark plug cap. Using the spark plug wrench provided in the tool kit,
remove the plug by rotating it counter-clockwise.
3. Reverse the procedure for spark plug installation. Torque to specification.
Normal Plug
The normal insulator tip is gray, tan or light brown. There will be few combustion deposits.
The electrodes are not burned or eroded. This indicates the proper type and heat range for the
engine and the service.
The tip should not be white. A white insulator tip indicates overheating, caused by use of an
improper spark plug or incorrect carburetion adjustments.
Wet Fouled Plug
The wet fouled insulator tip is black. A damp oil film covers the firing end. There may be a
carbon layer over the entire nose. Generally, the electrodes are not worn. General causes of
fouling are excessive oil, use of non-recommended oil, improper use of the choke, or
incorrect throttle body/carburetor adjustments.
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