I got a 75 sporty with a strange oil leak. All of the engine oil leaks into the primary case when the bike sits for a long period of time. I imagine it's a seal somewhere. Any ideas before I start digging into it?

 

The "check valve"spring is probably weak or the ball isn't seating properly. The oil leaks from your oil bag on the side of your bike down into the bottom of the crankcase. (This is what you have to fix)

From there is moves through the "transfer valve"into the primary side of your cases.

Here is a pic of the transfer valve between the crank case and primary side.



This can be dangerous as the transfer valve is a one way valve and will not allow the oil to go back to the crankcase side = RUNNING ENGINE WITH LITTLE OR NO OIL!

Skinner

NOTE: Probably be better to post these kind of questions in the "Ironhead" section to get faster response times.

 

CS200 - There is actually a thread going on about this subject in the IH section right now.

https://www.hdforums.com/m_3351791/m...tm.htm#3442606

"1970's a puker"

Same thing only his oil is staying in the crank case side and puking out the vent tube when started. Where as yours is going through the transfer valve into the primary side.

Skinner

 

I got the transfer valve out. How do I know if it's bad? It has some marks on it from someone using a chisel or something to remove and install in the past. Also, should there be a sealing washer or something behind it? There wasn't.

 

I just saw an illustration of a new one and there is a screen. There's not one on mine...

 

I have that 70 puker. Had the primary cover off for a new gasket. Loosening one of the bolts holds the chain adj bracket on caused oil to weep in from my crank side.&nbsp\\; Remote idea but something else to check. Hermit