my buddy has a ported shee with +4 timing, pods, shearer inframes, shaved head, i think around 150psi each cylinder, runs 1/2 race 1/2 93 oct. 15 tooth front sprocket. doesnt feel like its pulling that great up stairs. started with 340's now at 380's getting better but not sure if 400 is to big,this is also with stock carbs or if i should go smaller than 340's just dont want to go to lean or should i keep going up thanks in advance