white smoke coming from vacumm that comes off breather tube  By  marcus22 (Read 6,227 times)

Can you post a pic of the tube? If you can get a pic or vid of the smoke, that would help to.

Air-cooled? Or watercooled?,, watercooled head gasket went away,,, air-cooled? Broke a ring

Back when I got into engine boring with BBK's I broke a ring during installation and decided to just use the one I had left. Sure it worked, a LOT, felt like a 2 stroke, but it backfired a lot and overheated. So in short yes you can still move with a broken or even a missing ring. White smoke though, look at it in a dark area and shine a ultra bright light through the smoke, make sure it is white and not blue because they sometimes look similar until you get a white light on it in the dark.

White smoke is gasoline. Blue smoke is oil. Sometimes it can be both.

It def sounds like you have a topend rebuild in your near future, or a dead scooter if you don't do the top rebuild.

I agree, looks like you are going to have to pull the head at least. Hopefully it's just the head gasket, otherwise you will need to check the rings, and re-hone the cylinder if it's not damaged.

New rings will cost around $10. The gaskets; even less. Just some elbow grease, and 20 bucks or less. Sounds like you did break a ring, the top one. The other one starts fluttering when it gets hot, because it is not designed to take the blast. Whatever size the engine is, just type in "rings and gaskets for ________ size GY6". If it is a 50cc, you most likely need 39mm rings, like my Jonway had. Some have 44mm rings, though. My 2010 did, but it wasn't a Jonway, though it's only a "Jonway" because of the plastic body.