2010 Arctic Cat DVX 90 / 90 Utility ATV Service Manual, Page 10Get this manual
Testing Engine Compression To test engine compression, use the following procedure1Remove the high tension lead from the spark plug2Using compressed air, blow any debris from around the spark plug
CAUTION
Before removing the spark plug, be sure to clean the area around the spark plugDirt could enter engine when removing or installing the spark plug
! WARNING
Always wear safety glasses when using compressed air
3Remove the spark plug; then attach the high tension lead to the plug and ground the plug on the cylinder head well away from the spark plug hole4Attach the Compression Tester Kit (pn 0444-213)NOTE: The engine must be warm and the battery must be fully charged for this test
ATV-0051
Adjust the gap to 0.6-0.7 mm (0.024-0.028 in for proper ignitionUse feeler gauge to check the gap
5While holding the throttle lever in the full-open position, crank the engine over with the electric starter until the gauge shows peak reading (five to 10 compression strokes)NOTE: Compression should be within range of 195-230 psi in the full-open throttle position