Topic: Slow oil leak from sprocket area -CB750K2

[andy750]

I have had this persistent slow oil leak for a while now. At worst it costs the sprocket area with some sludgy oil (eventual result) and a light film of oil on #2 lower pipe. Back wheel gets a little dirty on on the rim and rear sprocket. Small spot of oil where the sidestand rests on the ground. Annoying more than anything else. So in my quest for a clean bike I am attempting to locate the source of the leak. Things done so far:

1. Plugged the chain oiler with a 19 mm bolt (from Yamiya) - now dry and no leaks from here anymore

2. Changed the gear cover gasket - now dry all around the cover.

Oil appears to be coming from behind the sprocket.

Here it is cleaned up:



Question 1: is this normal or is it a patched hole?



Question 2 - how easy is it to replace the big rubber seal? Do I need to split the cases?

thanks
Andy

[nancy]

Hi Andy
I can answer Q2 as I've got that T-shirt!
That seal picks out easy..hence mine was not in properly at all after a previous excursion in that area and I had oil leak down side stand area etc. Your seal may need chucking. It will push in with a piece of wood and mallet. But - no to case split..just pull the seal out from where you are at now.
Dunno about that plugged hole...
regards
mark

[andy750]

Thanks Mark much appreciated. I have the seal on order so will try that first. I hope you are getting some  riding in!

cheers
Andy