My Eiger has a weeney CVK32, and I've seen that most sport quads in the 350-400 range have much larger carbs (we're talkin' 4 stroke here). What's a good carb to use to bump up air/fuel flow? 36mm? 39mm? 40mm?? (!!!)

I'd like to preserve some idle quality.

I'm also planning on opening up the exhaust with some custom work, so that's gonna take care of that issue.

 

If you give a motor more carb that it can handle the air speeds will be too low and it will run like crap. You probably shouldnt go higher than a 36. My only question is why.... I doubt that motor is made for top end which is the only thing youd gain with a bigger carb. You really shouldnt bother unless you get the head ported, go with a bigger camshaft with more duration, and get a free flowing exhaust.

 

With a larger carb you gain throttle response, torque, and high end power. More airflow/fuel flow = more horsepower. If the carb is small, it reduces cylinder pressures, as there is a pressure drop after the carb.
Yes, 36 is what I'm looking at, but the Z400, which has a very similar engine, sports a 39.5mm carb. WAY bigger, but they run and idle great. Probably has a different cam, but that would only make idle worse if anything, as lift and duration affect idle quality.
Think about the guys that get 650CFM 4bbl carbs for their Jeeps/Chevys. They don't need to change to a performance intake because the carb is the restriction, not the intake. (to a certain point, I'm sure dual 4bbls would be absolute crap without a super high-flow intake)
I'm asking the Q because I don't know, beyond the Z400, what other smaller displacement quads are running, and if I get a consensus, then I should be able to make an informed decision on what MY 400 can handle.
For instance, what size is the carb on the Wolverine? On the Warrior? How about on the 400ex? We're pretty much talking about similar, 4 valve, single cylinder, 4-strokes here, nothing like comparing a Banshee to a Raptor.

But, you know, thanks for replying. The more info the better.

 

IF the motor needs it. Jakal was right on target with his post. If you go to a bigger carb there is a good possibilty that you can lose.