34mm best size?

[Skyman]

I have a 65.5 mm pistons stock stroke with a cool head. Dmc pipes with vf3 reeds & spacers and boost bottle kn air filter.
Q: Can I run 34 mm carbs or should I stick with 28s.

[audioworks04]

You can run them just fine and will see a big gain. You will need larger intake boots and I would ditch that boost bottle, all they do is cause cracked intake boots. I would recommend some port work also, will make a huge difference.

[Hondamaster5505]

Honestly without more motor work like porting or a stroker set up, larger carbs are not necessary. You will not gain much more power. Actually quite a few people have said in the past that they feel they lost power from going too large on a stock motor.

If you don't ever plan on porting the bike or anything, go with the 28's. If you have more planned in the future, then 34's.

[HondaPohl]

What are you gonna run, PJ's? They worked great for my setup but I had a little bit more work done to my cylinders. LIke Honda said on bone bone stock you might loose out alittle. Plus I dont know if those pipes are helping you out at all.

[Muggzy]

Stick with 28's. Bigger carbs need a MUCH bigger air flow you may pick up a little on the top end but low and mid is gonna go in the toilet.

Here's a little experiment you can do:
Purse your lips like you're gonna whistle but suck in. The "pull" you feel against your lips is the venturi/bernoulli principle. It's what sucks the fuel out of the carb bowls as air is pulled through the smaller (Venturi) opening in the middle of the carb.
Try the experiment again but widen your lips a little as you do it. You'll quickly lose the pull on your lips. That's what happens when you get too big on your carb. You'll need such big low and mid jetting that you'll practically be dribbling fuel and your throttle response will suck (no pun). Now if you're gonna drag race, the WOT is all you need :eek2:

x2 on the boost bottle - ditch it and get a stock cross-over tube.

[Hondamaster5505]

I wish I could find the link again, but boost bottles were actually dyno tested, and it was proven that the stock crossover tube actually made like 1.5hp more on the top end over a boost bottle. Ditch it and put a stock crossover back on.