[ChrisJ748]

Good evening guys (and gals if there are any) been a while since I posted last, mainly due to work and house moving etc. The question I have, I have had an oil leak somewhere on my horizontal piston for some time now, but in recent months, the amount of oil is starting to increase (not excessively) I've checked the rocker covers for leaks, and all look dry, so the only thing I can think of is the O-Rings between the head and the piston block. I've ruled out the lower end of the piston block for now until I've investigated the head to block leak (assuming this is where the leak is coming from)

So I've identified the O-Rings specified in the parts catalogue (Item No 8 :- 93823.3081, Item No 9:- 463.2.019.6A and Item No 10 :- 0400.17.030) Has anyone had any experience dealing with these O-Rings? are these "generic" O-Rings I could get from an automotive store bought as a kit?

The nice weather is approaching fast here in the UK (was a nice day today to ride!) and I'm itching to get back out on the bike, but I want to fix this leak first!

Any help would be greatly appreciated.

Chris.

 

[ducvet]

The ST2 and paso 907 bot had heat issues at the heads between the rear cylinder studs above the exhaust ports. the head will warp slightly and then you lose combustion seal which causes a leak. If you remove the head and cylinder and lap them together to restore head to cylinder seal and install new o-rings you will fix it until it warps again. If you install a big bore kit it will happen sooner but the fix is the same.

 

[Joyauto]

Lap head to cylinder

"If you remove the head and cylinder and lap them together to restore head to cylinder seal"

How do you go about doing this?