Possible Seal Problem

[Yamahauler]

The Tri-Z is running like crap right, now, there is no low end, if you dump the clutch it slows the engine down then slowly creeps forward. When you get to 5th gear WOT, it bogs and then if you let the throttle off to about 7/8th it is alright, but not good.

The plug is a gloss black. I was talking to a member on the board, and he said it could be a bad crank seal and trans oil is getting in.

The bike has a cobra pipe and a shaved head (I assume, it has 190lbs of compression). The carb has a 480 main, stock is 470. The pilot is a 55, stock is 45.

I was thinking it was running very rich, but now I am wondering about other things that could be wrong.

[twgranger]

WOW! Is that a new plug? How long did you run on that? I have seen bad crank seals do that to a plug. Are you loosing oil?

[Yamahauler]

It was a brand new plug, 15 minutes of regular riding.

I tried doing a plug chop, got to 4th gear WOT, but when its wide open, it kind of bogs, I held that for about 25 seconds, then went down to 7/8 throttle and shut it off and pulled the clutch.
The plug showed nothing, it still looked brand new, I couldnt figure that one out.

[sblt500r]

do you still have compression? hows the spark?

[Yamahauler]

190 lbs of compression, spark seems nice and blue

[TeamGeek6]

That looks fuel fouled. Oil fouling usually leaves a black, fluffy deposit on the end of the shell (ring around the plug the ground electrode is welded to.) Id go a -lookin for carb problems on this one.

Id experimented with a new crank seal design that leaked trans oil, and I got a black fluffy plug with liquid deposits on the plug ceramic.

Blue spark is probably OK.