ok i have the cylinders bored to 65.5 it has a cool head and V force 2 reads and i have t5 pipes it has also been ported and polished with stock carbs and intake boots the needle clip is all the way closes to the needle side and if i remember right i changed the jets to 350 jets but not possitive ill check when i check the pilot jet also but i had the same problem before jetting it. and my altitude is 4,487 feet but i have been riding in the mountains a lot on the snowmobile trails and the altitude there is 7051 feet and about 20-30 degrees the altiitudes i ride in the summer are about the same but the weather is about 70-90 degrees. so your saying i could have the wrong pilot jet size also would this cause my engine to brake a ring on that side thats why i had it rebuilt?