Oil pump?

Thebudman · #1 02-21-2006, 06:56 PM

I have a 74 sportster100cc, recently redone I'm having a problem with the transmission filling up with oil.
I've drained it all out and started over 3 times. At first I thought it was burning alot of oil, but once the clutch started slipping I pulled tranny plug out and got 3 quarts of oil. I'm not sure if there is an overflow that drains into the tranny of if there is a problem with the check valve in the oil pump. I would appreciate any help. Thanks

SKJOLD · #2 02-21-2006, 11:37 PM

Was the tranny recently rebuilt or did you have any major lower end work done recently?

pococj · #3 02-22-2006, 12:27 AM

Does this happen when sitting, when running, or ...?

Thebudman · #4 02-22-2006, 08:51 AM

The engine was taken apart for rebuild and the crank bearings were replaced. I'm not sure if it's doing this while running or sittng. The bike runs great. At first I thought it was doing this while running but now I'm not sure.

pococj · #5 02-22-2006, 09:00 PM

If it's been sitting for a bit, and you start it, it would blow oil out the crankcase breather if the oil pump check valve was bad. If it's not doing that, the check valve should be OK, and the problem is probably in the crankcase. Oil can make its way past the sprocket shaft oil seal into the primary. The primary & tranny share oil. There is also a one-way valve that is supposed to return excess primary oil to the crankcase. If this goes bad, it'll allow crankcase oil to drain into the primary. It's been awhile, but I think I remember this valve being low and just in front of the trapdoor. Might be hard to see with the primary chain, etc. in the way.