Hello guys i know there are many jetting threads but none at my specs! So i have a yx 160(57mm stroke/60mm bore) engine on a honda c90 i run a keihin Pe 28 original carb i'm at sea level my pilot/slow jet is 35 and 2 turns out on the screw but it boggs at 1/2 throtle and when i rev it from idle i can see smoke going off the exhaust and it's not oil!also i have a litle bit of worked ports on the stock head...any sugestions???