Oil coming from header

[incrediblehark]

I finally got my bike done and put together last night. Started second kick and everything was looking great. The I started to see smoke coming from the exhaust and the header. Checked it out and oil was dripping from the engine under the header. I took the exhaust off and saw this. Is this a piston ring problem? It's the only thing I didn't do anything with when I rebuilt the engine. Someone else told me that it could be that the crankcase was overfilled. Btw the bike is a 78 cb400t for reference.

 

[Rich Ard]

Did you check to see if there's too much oil in it? :

 

[incrediblehark]

Oil is fine. Just checked it.

 

[DoubleClutch]

Did you do a valve job on the head? Valve guides are going south. If the crankcase was over filled it would just pump it out threw the crankcase vent.

 

[incrediblehark]

No the valves were fine. I guess the only way to find out what's going on is to pull the engine. It just sucks because i just finished putting the whole bike together.

 

[chicano]

I've got one of these and it did the same thing. Did you change the Valve Stem Oil Seals?

 

[DesertKZ]

I've got one of these and it did the same thing. Did you change the Valve Stem Oil Seals?

X2, vacuum will pull oil through cracked/leaky valve seals. You should be able to replace those by just pulling the top end. (I just went though this on my KZ but the intake side.)

 

[Rich Ard]

If you're getting blowby past the piston you'll get oil in the combustion chamber. Check compression and do a breakdown test first to figure out where the oil is coming from.