I'm no pro but, if your running 14/40 gearing and running 20's on back, your blaster doesn't have alot of torque for that reason. i got stock gearing and 18's and i can only wheelie in 3rd gear cause i'm limited on torque...... so....... best thing to do is to either go one size tire down or you can decrease the rear sprocket by 1-2? .Since you brought up fuel ratio, if you running Bel- ray , amsoil or any other oil that says it can be premixed up to 50:1, dont take my word but your running rich. i run bel ray mc-1 at 50:1 with 110 octane. maybe you should try 40:1. I'm giving you my honest answer. hope this helped!