2003 Polaris 3 PRO X Factory Service Manual, Page 84Get this manual
ENGINE Piston Wash and Spark Plug color
Changing temperature, barometer, altitude, and fuel supply are just few of the factors that can affect the day to day performance of your engineThat is why using Exhaust Gas Temperatures (EGTs) are important for maintaining optimum performanceThere are two methods for helping you determine what the EGTs are for your machinePiston wash and the coloring of your spark plugThe piston wash is by far the most valuable tool in concluding EGTs, with the spark plug color running distant secondUse the illustrations below to help you establish the EGTs for your machine
Piston Wash
Spark Plug Color
Wet and Black wash indicates too rich fuel mixture Wash