I've got a 88 250r that fouls a plug if i'm riding in tight woods or if I hold it wide open. Do I need to rebuild the top end or what?

 

Is your airfilter clean? You need to rejet.
ERIC

 

An engine that fouls plugs so often should have a very rough or uneven idle if the problem is too rich a mixture. It could be jets or worn 0-rings within the carb. If this a 4-stroke, look for black smoke when you rev the engine. There should be none at all.

 

i got the same problem,after about 2 gas tank got to change the plug,the plug is brown do.a good think plug are cheap.Can wait for the end of this month im bringing my motor to Duncan to get a complete engine rebuild.i havent deside what kit im going to get, any suggestion would be appreciated.