Oil fouled plug

So I've finally put my bike on the road a few days ago. All in all it seems to be running pretty well. Plenty of power, and I'm still in awe of the acceleration.

I have yet to do a running sync and carb tune. But I have been checking the plugs pretty frequently and making some minor adjustments to make sure I'm not running too lean. I plan on doing a sync soon.

Anyways, on to the problem. I've noticed a good bit of backfiring in my right exhaust, and the plug on my fourth cylinder seems to be getting some oil fouling.

I'm going to double check the valve clearances on that cylinder and maybe do a compression test.

Anything else to check or try ?

 

What color are the plugs?

 

Dry compression test first and then wet. Just add a teaspoon of oil to each cylinder before you test.
Remember to hold throttle wide open and unhook your TCI

MN

 

Sure it's not fuel fouled? That could explain the backfire as well...

 

I'm not sure whether it is oil or fuel fouling. I'll take a picture in a bit.

The rest of the plugs are white, with a bit of tan beginning to show.

 

Here is the plug in question






The other three all look like this


Mixture screws are all 3.5 turns out. Main air jets are 205s I believe

 

that's just not firing, buy a set of plugs. put a good old one in that cylinder and new ones in the others, see what happens. no use in putting a new plug in there, you might foul it out too. you have have three testers

 

If it wasnt firing wouldn't I get stumbling and bad performance?

 

That looks fuel fouled.

 

"If it wasnt firing wouldn't I get stumbling and bad performance?"
you have it, you just don't know it yet

 

Sometimes in a pinch with no access to a fresh plug, I'll dry out a fuel fouled plug...sometimes I do it just for entertainment....it's pretty amazing how much fuel is actually capable of soaking into them.

I'll gently lock a vice grip onto the terminal, and lay it down on a gas stove so the firing end of the plug projects out into the burner flame.

After a minute or so, as the plug heats up, it will flare off a big flash of flame...then again, etc...just keeps popping off tongues of fire seemingly endlessly the longer you leave it there...always surprising there can be that much fuel on that insulator, even after air drying for a time...

Sometimes they get dry enough to fire if they weren't sparking, but never run right again.

 

Thanks. Guess I'll grab some fresh plugs then