Topic: Oil out of exhaust Part 2

[cb650guy]

I started this thread several days ago:
http://forums.sohc4.net/index.php?topic=80271.0

I wanted to give an update now that I have the bike back in my own garage.

The mechanic returned the bike to me tonight and it runs great with the exception of oil coming out of the exhaust. 

Now, as soon as the bike starts a blueish white smoke comes out of the exhaust.  This alone does not make me worry.  However, there is also a slighty drip of oil out of two of the exhaust pipes (4-4).  It is a real slow drip, but it is certainly liquid oil coming out of the bike.  I already rode the bike around and put some seafoam down the spark plug holes but the liquid oil remains.  What is my next step?  From here, I guess I need to take off the top end and post some pictures.  What should I be looking for?  What sounds like a likely culprit?

Thanks,
Adam

[kck3]

I didn't look at the link to part 1, so this may be a dumb question-are you sure its oil?  A friends bike was not combusting all the gas in the cylinder and it was coming out the pipe.  Gas+soot in pipes= a blackish liquid coming out of one of his pipes. 

[cb650guy]

That is a strong possibility.  I noticed that the pipes where the oil was coming out of the exhaust were slightly cooler when I started it up.  Maybe they are not firing and the gas is coming out the back end.  Does that seem possible?

Also, if all cylinders have good compression whats the chance of a the piston rings being shot?

[kck3]

If you have good compression then the rings should be good.  Have you looked at the plugs?  Are any of the plugs badly fouled?

[Hush]

Yeah don't rip her apart yet mate, it sounds like you have yet to put your finger on the real problem.
I tore my partner's GSX400 down to the pistons and the problem was an external part I could ahve accessed without all that grief.
If it runs OK I'd ride it some more, give it a good burst up some long straights (OK if it is an oil supply problem you may cook your engine and do irreparable damage so this is just what I would do)
She could be trying to extrude crud from being laid up for a while, unfortunately you can't remove baffles on 650 Hondas like you can on good ole two stroke twins.
You could remove the pipes and give them a good clean out though, that would also tell you if oil is coming from the headers by them being wet inside.
They should be a nice dry black powder sooty look.

[lrutt]

First off, you can have good CR and still have shot oil control rings.

Also valve seals can be a source of oil in exhaust. Those are really your only 2 options.

I'd run it a bit, good and hard, wtih new plugs, then pull them and read them. That will tell if it's gas or oil or just some residual crap.

[cb650guy]

Ok, I will run it some tonight and report back this evening.  Regardless of the black liquid coming out of th exhaust isn't the bluiesh white smoke a large enough cause for concern?  Is it possible that will go away as well?

[Bodi]

It's a cause for concern yes. If the plugs are not fouling and the bike runs OK, oil is pretty cheap when compared with a rebuild just to reduce consumption. Helps reduce rust inside the exhaust, too!

[KingCustomCycles.com]

Head gasket or a bad seal in the joint between the head and block?  You need to pinpoint the exact point it is coming out.  Clean and dry the engine with mineral spirits and compressed air.  Run it 10 seconds and look for oil, run it 10 more, and look for oil.  Eventually, a small shiny spot will appear at the exact source.  If it is inside the cylinder and only exiting the pipe, run it untill you are sure it won't go away on its own. A bunch of air flowing from teh crankcase or valve cover vents is a good indication of blowby on the compression rings.  What are your compression numbers? 100 or more is OK.

[Mainerider]

Adam
How many miles on your bike and how long did it sit? One of my two Customs had 4800 miles on it and had sat for a long time. Started having the same symptom after I put a few miles on it. Rode fairly hard and within a few hundred miles the white/blue smoke was gone. Unless you have more miles on it than the Space Shuttle chances are the internals are fine just crudded up from sitting. I ran seafoam in the gas and also in the oil for a bit then changed the oil again. Did a full tuneup inc valve adjusts and it runs great. Have faith in Honda-San

[cb650guy]

I dont know the compression numbers, I have a compression gauge ordered from Harbor Freight on the way.

The bike only has 89XX miles on it so it must have sat for a very very long time.  Maybe it is just crap in the engine.  I already run seafoam in the tank, but I will add some to the oil then do a change in 100 miles or so.  Expect another post in a week or two weeks with part 3!

Thanks everyone,
Adam