finally got rid of my stumble from about 2500, to 3000.

I know no one has probably had to do it....but i took some 800 grit sand paper and shaved about a half step out of those plastic donuts that hold the needles in my bs34 and voila....yes, they had to be lowered! Carbs have throttle shaft seals, mixture orings, float valve orings, 45 pilot, 140 mains. Even did it with the stock pilots. Plugs are over pilot jets. Best part is, if i need to back i can shim them back to stock. Uni filters too!

Thought i would share. Bike runs great now, i can cruise in low rpms and actually get on it without it cutting out. Turns out big mains really can bleed over quite a bit. Still have a small lean surge near redline, very small. Might try 142.5 mains.

probably a silly question but you don't have the canadian needles? is your bike an import from the us?

Actually, they are american bs34 on my 74

I'll have to look into this. I have the BS 34s and I'm getting really bad stumble at about those same RPMs. I'm going put in a new needle jet and mains, but maybe I'll try this first. Thanks.

I only neede about half a step sanded off. Used 800 on glass, best part is, you can shim back to stock if need be. Just kept stock one side by side with my shim so i could see the difference.