I have an 02 raptor and i just rebuilt the top end with a .30 over 11:1 wiseco piston and a stage 1 camshaft. I put a K&N powerlid on it with just a stock air filter. They gave me jets and everything, and the quad runs great until i get a small backfire and a bog when i go for a low torque after gettin a wheelie up and try to ride it. I turned the air/fuel mixture screw 3 turns out like it said, but still does it.Other than that it idles fine and runs great. Does anyone have an idea of what the problem could be?

 

You are running rich my guess would be the stock air filter you might want to try replacing that with a K&N because a stock air filter is pretty restrictive. When it bogs down low you are running rich if it pops and cracks up top then you are running lean.

 

If I add a K&N kit on my 02 raptor with a powerlid already, would i have to buy another jet kit? I live in northeastern OH, just wondering what a preference of jets would be with both powerlid and intake kit. thanks

 

with the mods that you have its hard to say exact jetting. Its something thats trial and error...... I currently have a 177.5/172.5 on order for mine because I put in a 180/175 and it was running a bit rich so I tried a 175/170 and it was running lean. The K&N powerlid that you have is almost useless with out a K&N airfilter because the stock filter still won't let more air in. K&N airfilter is one of the first things I recommend to anyone because its instantly more air. I have my lid removed with a outerwear cover for the airbox. You can usually buy jets at most ATV shops for around $2.50 each instead of going out and buying an entire kit. Also make sure that you have the jets in the right carbs the larger jet goes in the left and smaller in the right. This is looking at it from the back of the quad if you have them switched it will run rich and crappy. This is because the left feeds 2 intake valves and the right only feeds 1.