Trying again: 150cc craigslist scooter

[fratermus]

Originally Posted by Weldangrind

What did you find on Tuesday?

Confusion.

I drained the case and added a measured 800ml. This took it to near the top of the hatchmarks on the unscrewed dipstick. Nothing foreign in the strainer or on drain plug.

Installed the catchcan on a dipstick adapter for testing; if it worked I'd move it to the valve cover breather.

At idle (and with the valve cover still vented with a 2' tube) there is so much pressure that oil was pushed up about 1.5' up the new dipstick-attached tube, just short of the catch can itself. I revved it and oil blew out of the top of the catch can like a water hose. I would say at least 400cc was ejected in a couple of seconds.

Could blow-by really be causing this much pressure? Maybe there is a blocked oil passage and the oil pump is forcing oil out some other path of less resistance?

If blow-could cause monster pressure like this I guess I need a compression tester to see how the piston is doing.