Does air filter size make a difference?

[masterbs]

I am looking to put a K&N air filter on my 150cc ATV. I can only mount it coming off of my carb. The size filter I can use would be 3" round and 2" length. Is this going to hurt my performance by using a small filter or is this size ok?

[flyin#5]

clamp on filters are always risky... especially a k&n. they dont filter as good as foam. but if your doing it... the smaller filter should be just fine, especially since you wont be running it in the airbox.

[bwamos]

Is that 150cc's a 2-stroke or 4-stroke.

Should be ok on a 4-stroke.. but that's going to be pretty restrictive on a 2-stroke.