2008 Arctic Cat 366 ATV Service Manual, Page 14Get 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
2Rotate the crankshaft to the TDC position on the compression strokeNOTE: At this point, the rocker arms and adjuster screws must not have pressure on themNOTE: Use Valve Clearance Adjuster for this procedure