Comet Primary Outer Case T5/4 Sealing

[b'knighted]

We always seem to assume that the outer cover is the culprit but the comet inner primary case can also be taken off and flattened by the same method. You have mentioned Hylomar but have you tried the factory seal - a paper gasket?
There is also the chance of oil entering the screw holes at the joint and leaking out around the heads. Some other makes use O rings under the screw heads although the silicon should work as well.

Cheers

 

[tatty500]

Hello,
Just a thought....
Has the primary chain rubbed through to the case screw thread just below and in front of the clutch on the inner case?
Put some sealant on this screw.
Are you using a paper gasket?
Best wishes
Tatty

 

[alscomet]

Craig, thanks for your reply,Blue hylomar is not that good it does not adhere to a surface like silicone sealant or threebond does,its ok when trapped between a joint but does not bond very well when squeezed out of the joint. What I would do is stick a gasket onto the cover with plenty of 3 bond and let it set, use temp studs to keep it in position, then run a good bead around the gasket and also let that go off slightly before making the joint, I would also go as far as wrapping the cover screws with ptfe tape just in case its coming along the thread, tighten the cover up and leave it for a day before filling,throw away the blue hylomar it will end up as little balls of blue in your chaincase
or in your pump if you use it on the oil circuit side.Alan

 

[craig]

Both primary case surfaces appear excellent, no marks, dings, chain rub at all, no apparent cracks....yes alway a chance of screw head leaks, so i think it important to get a toal flat surface up and around the screw holes

 

[craig]

It is indeed a possible leak around screw holes, and maybe i did not put enough of a goo layer around the individual screw hole gasket surfaces. I think i need to blue the case gasket surface and hone to determine how nice and flat all is. But the surface sure looks good!