oil leak from exhaust

[Anonymous]

I've looked through old posts and haven't found this exact problem. Oil is leaking from behind the exhaust flange on cylinder #3 and possibly #4 as well. When idling it is a fairly constant, but slow drip on #3. It runs from behind the flange, to the outer edge of the flange until there is enough to drip. It is not coming from the tach drive or cam cover gasket. As a matter of fact everything immediatly above the flange is dry. Cylinder #4 has some oil build up, but not enough to drip.

Last week the exhaust for #3 & #4 started rattling when under slight load, so I loosened it with the bike idling. Then I retorqued the exhaust down. I don't think the rattling is as bad, but I do seem to remember that while the exhaust was loose but not of,f a drop of oil formed at the bottom of the exhaust port.

So do I just need the head reworked or a whole top end rebuild. I did notice a little smoke today while idling, but from the opposite side. I figure it really needs a top end rebuild, but before I do that I will just buy another bike. I am wanting an 1000 or better anyway.

What are your opinions on the leak and such?

Thanks,

Billy Miles

[earlfor]

There are no oil fittings between the #3 and #4 cylinders. If the oil is not coming from the valve cover gasket or leaking from around the rubber end cap on the valve cover, then the only place it can come from is around the "O" ring seals on the tach drive. I would take some simple green, a brush and water and when the bike is cold, scrub that area thoroughly and dry it.
Then run the bike sitting on the centerstand and observe closely using a strong shop light. Blip the throttle off and on. I betcha you will see a drip coming from the tach drive. :-)

I dont understand why you would assume an oil drip onto the #3 exhaust flange would be indicative of needing a top end rebuild. Maybe I'm missing something here??

Earl

[Anonymous]

I'm sorry. I didn't mention some other problems. Such as leaky cylinder base gasket, but I thought if the oil was actually coming out of the exhaust port in a fairly steady drip it would be indicative of oil passing the rings in that cylinder.

[earlfor]

Normal exhaust gas temps are in the 1200F range. If you did have oil getting by the rings, it would become exhaust smoke. There would be no liquid left to drip from around the exhaust port. :-)

Earl

I'm sorry. I didn't mention some other problems. Such as leaky cylinder base gasket, but I thought if the oil was actually coming out of the exhaust port in a fairly steady drip it would be indicative of oil passing the rings in that cylinder.

[Anonymous]

Of course , I should have realized that. However, being a stay at home dad is bringing about early senility.

Thanks Earl

[earlfor]

Or, you've been overdoing it with the fruit loops and sugar. :-) :-)

Earl

Of course , I should have realized that. However, being a stay at home dad is bringing about early senility.

Thanks Earl

[Clone]

Oil could be coming from the valve seal, but for it to be a steady drip at the flange you would get a lot blowing out the exhaust as it smokes in the hot pipe. Clean the block well as previously recommended, run it for a while and then blow some graphite on the area above #3, you should get a good idea if it is coming from above or inside.