1998-2001 Yamaha YFM600FHM Grizzly Factory Service Manual, Page 105Get this manual
SPEED LIMITER ADJUSTMENT SPARK PLUG INSPECTION
IINSP Ito) ADJ
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
Standard spark plug: for USA DPSEA-9NGK for Canada DPRSEA-9NGK