Why did my '75 Shovel just start dumping oil out the breather line? I put it away after a night of riding without issue, the first start the next morning the thing is puking oil like crazy WTF?

 

Sounds like the check valve is not sealing. Oil gravity flows from the tank to the crankcase. Mine does this every now and then.

 

What he said , replace the spring and check ball they do get weak with age .

 

Next to starter issues, crankcase dumping is the next big issue. I changed checkballs, springs and oil pumps and never cured it. Just keep a pan under it on a cold start, and check the oil after warm up.

 

Thanks for the help so far!! Where is this check valve assembly?

 

Look at the top of the oil pump , it's under the small cap next to the tower . Al's right about half it doesn't stop it .

 

Last time I saw that on my shovel, it turned out to be the key way in the oil pump. The one inside case on drive gear. Don't ride until you check for pressure.