Nearly a $2000 O-ring. Or shim. Or gasket.

[dougie]

I dunno guys. When I got the bike there was no gasket or shim installed. The microfiche doesn't show either. I have done at least 1/2 dozen oil changes without the gasket or shim. No leaks and no oil pressure problems.

[DanielMc]

I dunno guys. When I got the bike there was no gasket or shim installed. The microfiche doesn't show either. I have done at least 1/2 dozen oil changes without the gasket or shim. No leaks and no oil pressure problems.

It's all about the canister depth. Look on Anton's page and you'll see that for round edge canisters (like you've got) there's no need for either a gasket or shim if the depth of the canister is between 3.1mm and 3.4mm (chart duplicated below). If your depth is less than that you might choose to add a gasket, and if it's greater than that you might choose to add a shim. At the very least have a look next time you're in there and see what your bike's depth is. As I mentioned in ZM's post about oil and filter changes, I checked an '87 mono and found the canister depth to be 3.7. That bike had no shim, but had been fitted with a gasket so the "true" canister depth was around 4.15mm - much bigger than Anton's 3.3mm ideal "O" ring compression gap. That bike had run like that for over 40,000 miles with no problems, but I was happier once I'd ditched the gasket and added a shim to give me a smaller gap.

[dougie]

OK Daniel - I will check next time.
I do know that the big o-ring comes out with evidence of compression (squared off) without looking brutalized.

[Ray from Indiana]

I throw those gaskets away and install without