M8 piston jets

[BigT]

What corrective action should be taken if any with the M8 piston jets when installing a new top end? I though I read there was a possibility of an issue with oil leaking from the seal of the jets.

[justaguy]

Torque check. M8's went to a gasket style seal instead of an o-ring. Chance they don't even torque initially. Usually you can turn them a substantial amount on checking.

[FSG]

I'd take them off to ensure the screws haven't mushroomed the material in the case that would prevent the jet and gasket sitting flush and sealing against the case.

A rather shitty design IMO

[yobtaf103]

Cometic do a replacement gasket C10174

[FSG]

32 thou thick I believe  👍  👀

[rbabos]

I'd take them off to ensure the screws haven't mushroomed the material in the case that would prevent the jet and gasket sitting flush and sealing against the case.

A rather shitty design IMO

I  concur. Would be good for 1940. Sometimes you gotta wonder, were they thinking?
Ron

[BigT]

Thanks for the replies!

[HD/Wrench]

Remove the jet run the screw in and back out to further cut the threads that is a self tapping set up . The plastic on the gasket is one issue simple enough to remove it , and re install the jet .

[BigT]

Can this be done with the lower end together in the bike?

[bigcraig]

Yes.

[les]

Yes.

...but be really careful not to drop the tiny screws.  However, there is enough room to get in there.  Use purple loctite (low strength).  Make sure to spray out the threads with quick dry electrical cleaner and blow with air.  Clean any oil off the screws threads the same way too, before applying the loctite.

Also, if I were doing it, I'd remove one screw at a time.  If the gasket is crushing and making the screws loose after a while, you could do one screw at a time and make a second crush on the gasket, hopefully smashing the gasket on the second torque so that it's at its final crush.  Maybe this will make a good seal that won't eventually loosen.