Need help diagnosing air in the oil.
1976 shovel head fresh top end.
runs great but the air/oil expansion pushes oil out of the filler hole.
running stock pump with performance cooler.
This may sound stupid but how is the vent? I had the vent tube on my Sporty pinched by the battery and after riding enough to get it warm, the dipstick would launch about 5 feet. Sure looked funny to a bystander.
I had that happen to me with my '74 FLH many years ago, and like Tool advised, check the vent tube for being piunched shut or some type of goober is in there restricting the flow.