I bought a YTM200EL that had sat since early 90s. I drained the gas and oil, rebuilt the carb and it ran beautifully...
After riding for a while it stalled out. Checked the carb and made some adjustments. Ran good again. Yesterday I went to start it and it smoked (white). Shut it off and breather is full of gas oil mix. When I shut it off a half cup or more of that mix (and quite aerated) comes flowing out of the carb.
I assume I am looking at head or piston issue? Thoughts? Suggestions?