Ozzykarlberg

I have a 2002 banshee have rebuilt 2 times and I hatethe twin carbs. Its now bored 30 over, aftermarket pipes, and I am now needing to bore it again Ill either go 40 or 50 over. I was really wanting to go to a single carb. I was just wanting to know which carb would be the better one to go with. What size i would have to go with. And if anyone has one to get rid of let me know.