Just had the cylinder redone with a 71mm piston. The bike has the original carb PJ 34mm keihin. It has no bottom end and sputters on 1,2 & 3rd, Once I hit 4 & 5th it clears up but still not the same. I have the air on so removed the lid same thing. I've gone and down with jet same... I've also tried different carb PWK same issue. I thinking it might be crank seals. Any ideas???