Oil Overflow when cold.

I have had the same exact problem and our engines are exactly the same, C-85 stroked to a O-200A unit. Before you even open the cowl, hand crank the prop 6 to 10 times. The oil will go to the correct level. For some crazy reason, it happens more when it is cold rather than hot!
Regards, Larry N93436

There’s a capillary action on the dip stick that makes oil sort of crawl of the stick when it has cooled down.
You should be wiping the stick down and reinserting it- when it’s cold-to get an accurate read. Sticking it while it’s hot won’t give you an accurate reading.

Ron, Thanks. I also thought of that. Problem, It's a C85 recently rebuilt including a new O200 crank. Why I'm not sure it is the oil draining back is:I have owned a previous C85 and never happened. B: No other Ercoupe owner that I have met has ever had this problem. When I start and run the engine and them check the oil it is correct on the dip stick. ????? Of courseit it is oil drain back but if I change the oil and use the correct amount, there cannot be more oil that can drain back. Thanks for your input. Larry

yep, gravity sucks, pulls everything down, including oil from the engine.

Is it possible that all the oil pumped up into the oil passages and chambers in the block when the engine is running, especially around the oil pump, slowly drains back into the sump when the engine is turned off?

take a read here and maybe some lightbulbs will click on and help you to solve your problem.

www.ercoupe.info/uploads/Main/breather_mod.pdf