Right side not firing-Oil in the Header

[kylechanh]

I've received so much help in the past to get my '64 CB77 running fine. Now I need your help again.

One day it just didn't seem that it had the power it once had. I discovered that the right side was not firing. I did a carb cleaning and rebuild, replaced the spark plugs and installed the electronic ignition. I must say that is started up easier, but the right side was still not firing! We did test and saw the spark plug working outside of the engine. Then I noticed a bit of oil on the ground and found a bunch inside the header. I am assuming that there shouldn't be oil in there and that it is causing it not to fire?

Any ideas on the problem and/or solution? Is this a whole engine rebuild? Please help.

Thanks,

[dkwilfert]

You probably already know, but if you need someone to tell you the bad news; yes, you have a serious problem. At a minimum the engine and head need to be pulled. Most likely a piston/ring issue, but could be a valve guide one.

In any event, you appear to have lost compression, that's why it won't fire, and with oil in the exhaust header it is coming up from the crank case through/by the piston or down from the head through a damaged valve and guide.

Possible, but very unlikely, you could just have a head gasket problem where you are losing compression and the oil passage from the lubrication system is somehow getting into the cylinder WITHOUT getting outside the engine at the cylinder/head interface.

Run a compression check on the dead cylinder just to be sure it is bad, but I'd bet you will be pulling the head to find the exact cause of your problem.