New top end...now fouling plugs??

[Steve10]

'96 YZ125...never had a problem fouling plugs before. Just put in new wiseco and had the cylinder replated at US Chrome. Running Yamalube 40:1. I haven't changed jetting or anything. Bike runs better than ever, tons of compression. I'm familiar with jetting my bikes and it runs clean all the way, but it's fouling plugs like crazy now. Plugs are wet and it's seeping spooge out the pipe/head joint. I'm thinking crank seal, but the oil level hasn't dropped yet and nothing out the crankcase vent. Admittedly I've taken it easy breaking it in, but it had more full throttle today and still fouled.

Anybody ever had this with a fresh top end?

 

[sick 96 250]

you say plugs are wet. What kinda wet, oily wet or gas wet. I know every time i've changed top ends on my bike and my buddy's 125 we had to drop the pilot a few sizes. If your wet fouling from gas check the float level. Friends 125 had that problem. Thought it was the rh crank seal but all it was is the floats were off. Good Luck and keep us posted

 

[Steve10]

Yeah, I should've checked the float level today. I moved the clip on the needle up one notch, and turned the air screw 1/2 turn out. I rode it a little while and checked the plug...it's still pretty dark but not wet. I'll get a leaner pilot also. I'll keep you posted.