Oil Leak Problem

D

dave48

Junior member
Location
Missouri USA
My 78 1000 has an oil leak that appears to be coming out around the exhaust flange of the #1 cylinder. What could cause this? It just started this yesterday after a long ride. There?s no smoke from the exhaust and the compression was checked recently and was OK.
Dave
 
Try fitting new copper crush washers in the downpipes.
Seems that if there is an air leak there it can pull oil down the valve guide.
 
If you want a bit of insurance smother some Loctite Blue Silicone gasket goo around the copper washer to make sure it seals nicely.
This tip was passed on to me by Mr Nairn and has worked a treat on my bike.
 
It's unusual for oil to be coming out of the exhaust port because the exhaust pressure normally keeps the oil out. That's why the exhaust valve guides don't have valve stem seals.
It may be coming from somewhere else like the head gasket or the camshaft cover gasket and tracking around to the exhaust clamp.
Have a look inside the exhaust port. If it's oily in there you may have other problems.
 
Grant said:
Try fitting new copper crush washers in the downpipes.
Seems that if there is an air leak there it can pull oil down the valve guide.
Click to expand...

Agree, had it happen to me, brand new chrome on the pipes too. A bit more of a nip up and fixed. Not that unusual Cam, maybe a little vacuum from the other pipes in the collector ........ like an automatic oil extractor (pardon pun).
 
The oil is definitely coming from around the exhaust flange. Since Wolfgang is out of new crush washers I took Simon?s suggestion of gasket goo. I?ll see what happens. I did have the exhaust system off last week to clean the oil filter.
Dave
 
Where are you Dave? I have some spare crush washers I could send you.

Otherwise you can get them from Aircraft Spruce
Part # AN900-24
1?" ID  1/8" wide, 3/32" thick
38.1 ID  44.45 OD

Cam
 
Dellortoman
I?m in the central US. Wolfgang is expecting a new shipment anytime. I hope the gasket goo holds till then. If not I?ll try Aircraft Spruce. Thanks for the information.
Dave
 
Take an old one to a Honda shop.
Used to be a Honda one fitted.
Not sure the model, maybe 750/4.
I think it's a sort of venturi effect sucking oil down the exhaust guide.
More common than you think Cam.
 
Honda 750/4 exhaust rings don't fit. They're about 5mm too small in diameter. I made one fit once at a track day when I was desperate. I had to stretch it by hammering it down over the neck of a beer bottle!

 
I recall using Honda CN 450 items, but it's been a while since I bought the last set for 35mm headers.
One of the local supply chains do these, which should fit.
http://www.polo-motorrad.de/de/auspuffdichtung-krummer-motor-2er-set-s410210012060.html
 
Check the exhaust flanges are flat...they bow which means they don't compress evenly. There are some aftermarket ones about...mine from Wolfgang work well and look good. Think Keith and Red do some too. Can be a sign of worn valve guides though. Gave up with those  bought new head and even that has a seal fitted on the exhaust valves. No leaks, no smoke, no oil consumption. Hope it's just the bad sealing in your case!
Nick7
 
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