1998-2004 Yamaha WaveRunner XL700 XL760 XL1200 Factory Service Manual, Page 41Get this manual
'''''''''''''' _ U_NI_T ER '''''' POWER UNIT Spark plug inspection 1Inspect: Electrode CD WearDamage ReplaceInsulator color Discolor Check the engine conditionColor guide: Medium to light tan color: Normal Whitish color: Lean fuel mixture Plugged fuel mixture Air leak Incorrect settings Blackish color: Overly rich mixture Electrical malfunction Excess oil used Defective spark plug
Spark plug Clean the spark plug with spark plug cleaner or wire brush3Measure: Spark plug gap Out of specification Alter gapUse wire gauge