1997 Yamaha YFM600FWAK ATV Service Manual, Page 74Get this manual
SPEED LIMITER ADJUSTMENTI SPARK PLUG INSPECTION
For proper throttle lever operation do not turn out the adjuster more than 12 mm (0.47 in)Also, always adjust the throttle lever free play to mm (0.12 0.20 in)
SPARK PLUG INSPECTION 1.Remove: Spark plug 2.lnspect: Spark plug type Incorrect Replace