I was thinking about buying a new carb for my 500 this coming summer, what should i get? i was thinking about the KEIHIN 39MM PWK.

 

Excellent carb, ran one on my 400 and also setup a zilla with one. Great throttle response and easy to tune!

 

do you know what the stock carb size is in zillas?

 

39 pwk carb is a great carb for the 500... I have one that i had Duncan racing bore to a 40mm and a pro-flow-mod
The stock carb is a 38 mm but the pwk is the way to go.
Duncan racing

 

will i noticed a great diff. on a basically stock engine with a PTR pipe with the PWK on it?

 

I have both the 39 PWK and the 38 Oval slide, it all depends on your riding, they are both great carbs, I leaned more for te Oval on the grounds in Glamis I ride midrange mostley, the 39 pwk is great mid to screaming top end. I may have one for sale soonI have two 39pwk, one bored to a 42mm and a stock one.