125-200cc How to check main crank seal?

2002 husky wr125. I had a lot oil coming of out my cylinder head by the exhaust port. Along out of the tail pipe. I removed the plug it doesn't have oil all over it. And it bogs down in first and stutters then it will go good. But I have to work the clutch to do it, almost like the plug is going to foul but doesn't. I removed my cylinder and measures the piston 54mm. Cylinder 54mm. Gap of the ring is dead on as well. I looked in the crank with a flash light and felt just a little bit of oil/gas mix and nothing like tranny fluid... I also stuck a q-tip with needle nose down the case to touch the bottom and it came up really clean. No tranny fluid. So I believe my seals are good on both sides .. No Pre mix or gas on my fly wheel. So I'm scratching for reasons. My reeds are fine no chips no breaks tight seal. I put new o ring s on th cylinder head. New base gasket as well.

My jetting was 400 main 35 pilot 3rd groove on the needle. I now lowered it to 390 main 30 pilot and 2nd groove on the needle.

The only thing I did add was That gasket maker sealer stuff I put a little on the base gasket on te bottom of my cylinder. Would that create a problem? And will just a Gasket and no rtv work? Or should I use it? Scratching my head with this problem. Been looking at the bike apart for a month now.

After reading through your older posts with pictures and comments and suggestions it looks a lot like you're getting water (coolant) into your combustion chamber. I just read above that you replaced the o-rings between the head and cylinder but in the photos from the previous post it looks like you removed the cylinder with the head still attached. Pull that head and see if one of the rings got out of the groove while installing and is letting coolant into the cylinder.
Water would cool combustion temps and keep oil from burning off (spooge), run like crap, create Cheech and Chong cloud....

I appreciate the reply. I'm going crazy here. I did take the cylinder head off and the o rings are new and still in place. I did put that gasket maker along With a new gasket on the cylinder base... I'm curious if that silicone s%#t would create a little gap to let anti freeze get into my piston cylinder ..

replace plug, sometimes a bit of the silicone will get lodged bewtween the porcelain and the body of the plug.post a picture of your plug, the crankcase draws vacuum so would suck air (stator side) creating a lean codition or oil deposits and excessive smoke (clutch side) your jetting may be out but also try a compression test.base gasket does not come into contact with coolant.

see how it says the inner and outer o ring properly greased...what type of grease is that? and will it burn off or will it create a better seal?..

and jo360 see on the picture the base gasket it has two holes near the exhaust port.. that has radiator fluid in it as well.. if you look in the 2 stroke forum i posted earlier yesterday i posted pictures of the cylinder head.

look at the picture i posted..and the comment.. thank you

hey mate... did you fix your bike???
i am having the same symptoms...

I think the grease is just to prevent the o-rings from sticking to either surface. I've always put mine in dry. No problems in the 4-5 top ends I've done on these bikes.

Have you checked your float height/jetting? What kind of premix do you use? What type of riding?

A leakdown test would tell you pretty quick if you have a compromised seal. But if your coolant/oil levels stay fine and the bike doesn't smoke white I'd think it has to do with your carb.

Is there much blow-by on the piston/rings themselves? Have you done a compression test on the top end?

mine bogged real bad in first, feathered the clutch and off she went. had a bad lean bog. i went from 400 to 410 on my main and dropped the clip the whole way and shes now a screamer.

My buddy put a bit of gear oil (100ml) in his tranny to check for a crank seal. You could smell the gear oil stink in the exhaust proving the main seal was gone.

and i was asking eric (and everyone else) about it two days ago...
your point?