How long do you'll recomend breaking in a new piston (bored .020)?

 

When i bought the 2000 Xplorer 250 the dealer told me a few tanks of gas before I open it up . just to be sure, I don't know how this applies to rebuilds but it bet it is the same. 3-5 tanks of gas would be right.

 

One tank, premixed to 40:1, along with the oil injection should be plenty. Lots of short trips where the engine gets up to operating temperature, then allowed to cool completely would be better than one long run. I broke in my 2001 Xplorer by riding it for about 30 minutes every afternoon until the first tank was gone. For a mixture of 40:1, that would be 12.8 ounces of oil to 4 gallons of gas, 9.6 ounces of oil to 3 gallons of gas, and 6.4 ounces of oil to 2 gallons of gas.

 

Did you foul plugs by running 40:1?