Topic: oil leak

[andy1976]

Hi all,
After managing to get my 750F running I took her for a short test run.
I got back home and noticed oil leaking from the cyl head.
What cause oil leaks and how do you fix them? 
other than this everything seems OK

Thanks
Andy

[Johnny5]

I had the same problem. My leaks were from not putting sealant on the 6 pucks. I tore it back down and cleaned up the pucks, added sealant and have been leak free ever since.

Where exactly is it leaking?


Mine looked like this on it's first couple of rides.

[andy1976]

I've had another look this aft and it seems to be coming from exhaust tappet covers on 1&4 so that can be easily fixed.
But..... on start up I get quite a bit of white smoke, which seems to thin out as the bike warms up. Is this a dodgy valve oil seal or is it still burning off excess oil from the rebuild?
I used quite a bit when putting it back together and I only did 2 miles when out doing a test run on sunday.

Thanks again
Andy

[OldSchool_IsCool]

R miles isn't enough break-in.  See what is happening after 50 or 100.

[Johnny5]

It is possible to put the valve cover on backwards. It looks symetrical but it's not. I had a thread about this and was able to take the valve cover gasket off and put it back on without removing the engine.

[andy1976]

I've done a total of 230 miles since I last posted, the oil leak has virtually gone and it stops smoking after a minute or two. I pulled out the plugs and they're all black and sooty.
Am I right in thinking that she's running rich?
Would a hotter grade plug cure this? The floats have been checked and are at 26mm.
RPM's Have been kept below 5 thousand as pistons and rings are new.
The plugs being used are D8EA

Thanks
Andy

[Johnny5]

Possibly. Or an ignition problem.

Is your intake/exhaust stock?

[andy1976]

Air box is stock, the exhaust is a Motad 4-1 (UK made). I recently found out these systems can "restrict" the engine, so it's recommended that holes are drilled in the back plate to let the engine breathe. I have not done this yet though.

[bryanj]

Motad do not "restrict" the engine, they are designed to be as quiet as a standard system and fit with no re-jetting as in UK noise is a problem at annual inspection (called an MOT here) you on the other side of the pond seem to be able to get away with just about anything with exhausts!!

[andy1976]

It's still leaking!!!!!!!!!!   
The tappet cover seals have been replaced and four bolt holes have been heli coiled as the rocker cover was also leaking.New rocker gasket. It looks as if it's leaking between 1+2.The head gasket seems fine. I was on the phone to a guy that I met at the local bike show and he said it may be the round disc under the cam carriers that may be causing it.
These round discs were replaced with new ones when I rebuilt the top end.

Any Ideas on this.  (This bike will not get the better of Me) 

Andy

[MCRider]

It's still leaking!!!!!!!!!!  
The tappet cover seals have been replaced and four bolt holes have been heli coiled as the rocker cover was also leaking.New rocker gasket. It looks as if it's leaking between 1+2.The head gasket seems fine. I was on the phone to a guy that I met at the local bike show and he said it may be the round disc under the cam carriers that may be causing it.
These round discs were replaced with new ones when I rebuilt the top end.

Any Ideas on this.  (This bike will not get the better of Me)  

Andy

The diagnosis is frustrating process, and the answer may not be fun. We've had several threads on this. But lets start from scratch. If the oil is coming from an area above the head gasket, but below the valve cover gasket, (similar to Johnny% picture) it is often the aforementioned pucks. However there is another place.

You'll need to clean it REALLY well, maybe spray some baby powder on it. Then run it. If the oil appears in those middle fins of the head, look in with a flashlight. 4 of the holes that the cam tower hold down studs/bolts go into are open to the atmosphere. You can see the bottom of them between the fins. Its the 2 at either end of the front of each cam tower, and they open right above each spark plug. If oil is dripping there that's the problem. It can run down into the fins and blow out in all sorts of places, so actually finding the source is key.

its either the pucks, or these screw holes, or both.

In my case it was because the threads had become so fatigued from multiple use, that oil would wick its way down there. A few of them had been tapped out to 1/3-20 and or new 6mm helicoils.

Some have said they install those with oil resistant locktite. For me it was pernicious and a cause for parking the bike and it is now undergoing renovation with a new (to me) head.

[andy1976]

Thanks MC.I'll do the baby powder trick tomorrow.

 Looks like its engine out time at the weekend.

When I put new pucks in I did'nt seal them, so maybe it's this thats causin it.

If you look at Jonny5 pic my oil leak is behind the frame tube.

[MCRider]

Thanks MC.I'll do the baby powder trick tomorrow.

 Looks like its engine out time at the weekend.

When I put new pucks in I did'nt seal them, so maybe it's this thats causin it.

If you look at Jonny5 pic my oil leak is behind the frame tube.

Yup, pucks or the outboard forward screwhole that opens into the #1 (or #4) sparkplug cavity. It will be dripping from the bottom of the hole which is the top side of the sparkplug. From there, with wind, it can exit the front or the sides of the cylinder head fins.
If you pull that bolt out you can actually run a wire or probe down from the top of the cam bearing and it will exit above the sparkplug, outside of the engine. You wouldn't think that it could leak oil, but it can and does.

Good Luck.

[OldSchool_IsCool]

I applied a thin coat of Permatex Aviation Sealer on my pucks.  No leaks from there.