1990-1998 Arctic Cat Snowmobiles Repair Manual, Page 113Get this manual
LUBRICATION, MAINTENANCE AND TUNE-UP
a light tan color after the engine has operated for awhileSee Figure 51The reach, or length, of plug is also importantA shorter than normal plug will cause hard starting, reduced engine performance and carbon buildup on the exposed cylinder head threadsA spark plug that is longer than normal could interfere with the piston or cause overheatingPhysical damage to the piston or overheating often results in permanent and severe engine damageIf the spark plug extends into the combustion chamber as shown by the too long view in Figure 52, carbon built up on the exposed threads may prevent the spark plug from being removedForcing the spark plug out will probably damage the threads in the cylinder headThe standard heat range spark plug is listed in Table 8It may be desirable to install spark plugs of slightly different heat range than listed to match operating conditions
Spark Plug RemovalCleaning 1Grasp the spark plug lead as near the plug as possible and pull it from the plugIf the spark plug cap (Figure 46) is stuck to the plug, twist the cap slightly to break it looseCAUTION Dirt near the spark plug could fall into the cylinder when removing the plug, causing serious engine damage