85 Atc250r Question

[Fox250R]

HEy guys! I just tore down a 85250R, painted the frame and rebuilt it back up..Before i did all this it ran awesome! But now im fouling plugs left and right!! And its just not fouling its flat out BLACK! IT smokes pretty bad when im riding and leaks oil out the header but it has tons of power for a stock bike It pulls wheelies in 4th with ease...After about 2 hours of riding it starts to bog down and then dies. I change the plug and then its rocking again.. Everything in the bike is stock as far as i know..Its running a stock carb with a 142 main @40-1 running Klotz oil and a B8ES plug..My needle clip was on the 3rd notch when i put it back together..The book says it needs to be on the 2nd i think, but wasn't sure if one notch would make it run that rich,and i didn't know if it was 2 notchs from the top of the needle or the bottom.. I dont think my rings are going it has good compression..I just bought a paul turner high rev pipe and im trying to get the thing running good before i bolt it on..Any info would be great!! THANKS!!

[x.system]

Move the clip to the second notch from the top and do a plug chop. One notch will make a difference and it sounds like you are getting to much fuel.

[Fox250R]

What the heck is a plug chop hehe?? And if im fouling plugs that means im getting to much oil right??

[hondawilly]

ya getting to much oil if its black

[petesatc]

check your gearbox oil....if it uses alot...it could be the centre crank seal...
they go hard after a few years..then drags the oil through the seal and into the bore....change your spark plug for a new one...if it starts sweet and then chokes up after a few hours...it's a good chance it's the crank seal...hope this helps

[TimSr]

Carb settings dont suddenly go out of whack for no reason. I would strongly advise not adjusting anything in the carb, until youve figured out what caused your sudden carburetion change.
What does "tire down" mean? Did you change anything in the motor, exhaust, carburetion, intake, or fuel mix? Was the engine disassembled? If it ran fine before, then something has changed, and while it may be inadvertant, I doubt your main jet or needle clip changed themselves. The only thing in the carb that could cause such a sudden and drastic change is something failing within the choke circuit.

[Fox250R]

all we did is tear down the frame and paint it thats it...but we took apart the carb and think we might of put the needle on the wrong notch..we had it on the 3rd and its supppose to be on the 2nd..Also i talked to a guy at white knuckle racing, he said the paint may be covering up my ground and given me bad spark resulting in fouling plugs so ill check that out too...