Hello, I'm new here.
I have an 86 trx 250R that keeps fouling plugs on me. When the plug fouls i can clean it up with a wire brush and it works. The carb jetting was to rich when I bought the bike so I leaned it out some. I have good spark but it still fouls plugs about every other day. The carb is a duncan racing PJ. When I bought this bike, i noticed it didn't have a voltage regulator on it. Could this be the problem? It runs fine without it.

 

you might have a leaky right crank seal. Usually a slightly fat carb wont take a plug out in 1 day.

 

would a leaking crank seal cause the trany oil to burn away and be low? The plug isn't oily looking?

 

of course it would. it usually wont be oily. Just fouled. Sometimes blackish

 

I had this problem with mine also. I just put a oversized cylinder on and new piston, changed my 2-cylcle oil. Have not fouled one yet. I do sputter on the low end. Any idea on that. it screams on the top end.

 

Yes, what kind of oil are you mixing it with. Mix it at 40:1 for all around use. some great brands are red line, amsoil, klotz, golden spectro, or any other name brands. Dont just use chain saw oil.

 

I'm using golden spectro oil at 40:1. I fouled 2 plugs today??? It seems to be getting worse. When I'm riding it will act like it just shuts off. I replaced the cdi box and coil but had no time to ride it and see if it worked. It seemed to start better. One thing I did notice is when I kick it over to check the spark it sparks good but right after I kick it, it will spark again when the motor isn't turning? Will it hurt the new coil and cdi box if I'm not running a voltage regulator?

 

ive been riding golden spectro at 40:1 for the past season and my two uncles ran if for years on their trikes, this isnt your problem. you got me stumped.

 

you need to break down and check your seal. 2 plugs in a day isnt right. You could run 16:1 and not foul 2 plugs in a ride.

 

i too have this problen on my suzuki right now.
i have checked jetting,carb float levels,had the lower end completely rebuilt, top end rebored and new piston,tried hotter spark plugs. it did this before the rebuild and still after [img]i/expressions/face-icon-small-sad.gif[/img] only thing left to check on mine is the electrical when i check my spark it looks like it should spark more than it does.