Your bore, axle, seat and gas tank don't have anything to do with this! lol! Like said before, it is most likely your jetting. I mix 40:1 and you'll probably find most guys mix between 32:1 and 40:1. Probably a few that mix thinner but not many. I would suggest checking your plugs. I usually start adjusting at idle. Set the pilots and air screw first. These supply fuel at idle, mid throttle and at WOT. THen adjust the needle. This supplies fuel (with the pilot jet) at mid throttle and at WOT. Then adjust the main jet. While at WOT you are using fuel from the previously adjusted pilot jet, needle position and main jet.
Since the pilot jet and needle supply fuel at WOT as well as the main jet, it is important to start the adjustment with the pilot first, the needle second, and the main jet last.
SP