Ok, I have searched and couldn't find anything helpful about my problem. I have a rocurring problem. I get an oil leak at higher speeds/rpms between the cylinder and the oil filler plugthrough the clutch cover gasket. I have replace the gasket three times now and it comes back. Maybe I am tightening the bolts wrong. I torque them down to about 13 nm in a criss-cross pattern. Is this too much or too little?

I use a new gasket as is, it has additional sealant from the factory applied in that area. The gaskets for the bolts go in between the bolt head and the cover, but that is not where it leaks. It leaks between the clutch cover and the crank case. It almost seems like crank case pressure is too high, but I checked the breather hose and it is not clogged. It's weird that it needs the higher range rpms to do that. I still don't know what the correct torque for the bolts is. Not even my original Suzuki shop manual says anything. It just says to replace clutch cover. How stupid! This needs to be a bit more detailed, other areas they show torque values where it really doesn't matter.

verslagen1 wrote on 10/21/09 at 20:17:27:

Does crank case bolts include the clutch cover to crank case bolts? I know they are 6mm also, but it has a gasket in between, the crank case halves have sealant only as far as I know. Or does it not matter? This leaking problem really drives me nuts! Every time I replace the gasket, after about 500 miles it starts leaking again n the same spot under heavy load. The mating surfaces are not damaged and the cover or crank case is not cracked or anything either. Sometimes there's a little coming out of the oil filler plug too.

Ok then I did it right then. I just don't understand the problem.

Why do your gaskets leak?



Part of the answer to your puzzle is the high pressure oil passage at the top of that cover.  The top gasket width at the top of that high pressure area is only 3/16 wide and the .020" thick gasket has to stop the migration of oil that is 1) hot !! and 2) running under 20-30 psi of pressure at full engine rpms.  

Hot oil can make it through untreated paper if not supported by an impregnation agent.

To do this the gasket must be impermeable to oil (completely impregnated with either rubber, vinyl plastic or silicone gasket maker) that has been allowed to set up completely before the gasket is installed on clean aluminum flanges, then the bolt up clamping pressure is applied.  

This way the fibers of the gasket material are reinforced and supported internally before the hot oil pressure is applied.  All the micro pathways internal to the paper are blocked before the hot oil pressure is applied.

A stock Suzuki gasket is rubber impregnated with a vinyl stripe going around this critical area (protruding vinyl that gets crushed into the gasket joint when the installation clamping torque is applied, so it makes it a "one shot helper" on the bare gasket installation).

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Since you have unusual re-occuring problems, try checking your cover for any warping or lack of flatness by putting the cover machined side down on a flat surface after removing the hollow steel locator bushings.  Check for any rocking or gaps.

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Other information is available in Tech Section here:

http://suzukisavage.com/cgi-bin/YaBB.pl?num=1256595298