Hey, I am having the same issue, I just did a complete rebuild on my machine, new piston/rings/valves, etc. I went 50mm over on the bore and it smokes for about 2 min after I start it cold. I have torn it down 4 times and cannot figure out what the issue is. I have only run 2-3 tanks of gas through it… I see you had this problem a couple years ago, what ended up happening?
