1990-1998 Arctic Cat Snowmobiles Repair Manual, Page 68Get this manual
CHAPTER TWO
may be too rich, but usually the low speed mixture is adjusted too lean
chamberIf the engine has been modified, the compression ratio may be too highDetonation may not be noticed, especially on liquid-cooled engines, at high engine rpm when wind noise is also presentUnnoticed detonation is often the cause of engine damage that occurs for no apparent reason