I'd posted this question in the thread I have going regarding my restoration, but haven't received an answer. I'll be a bit more direct and make a new post about it here.

It looks like there are two O-rings at the tach housing assembly #5. Does anyone have any info on replacing these? I've got an oil leak here and would like to replace them.
 

 

 

I've removed the tach cable and the bolt #12 holding the stopper #11 and have gotten the housing assembly to lift slightly, but it's tight at this point.
 
I don't want to force it if it's being held by the driven gear #6, or is it just the O-ring #7 holding tight? Is this O-ring in a grove in the housing assembly, or is it between the housing assembly and the driven gear? I really don't want anything to drop into the case for fear I'll have to split it to simply retrieve something I shouldn't have messed with.

Thanks in advance

Just google imaging it looks like the outer Oring is in a groove on the item that comes out so i guess its just hanging on & wants a twist & a lever upwards. The split collar for the internal small Oring could be fun to get out. Might have to get up from the bottom when the assembly is out & push on the small Oring which will probably destroy it to push the collar with flat washer out. Better wait until someone that's actually performed the operation comes along. I'm only looking at pics. Small Oring isn't the best plan for something spinning but i guess it does the trick or it'd be a proper seal.

The housing is a tight fit. You can remove it with no issues. If you need the o-rings www.rockymountainatvmc.com  has both in stock.

Got it!