I have an 05 Raptor that I just put a Twin Air filter on and removed the spark arrestor/baffle. I jetted it up so my mid range and top end run perfect. But I'm having trouble with the idle and low end circuit. If I pin the throttle quick, it dies. Also, when I'm putting around in first gear just touching the throttle, it hesitates bad. I bumped the pilots up one size. What should I do next?

 

try turning your Air fuel screw out, or put the smaller pilots back in, or move you needles down by going up one on the clip. One of those should help.

 

I adjusted the mixture screws from 2 1/2 turns to 4 and everywhere in between and get no change. And wouldn't I need the bigger pilots because of the change in the intake and exhaust? The needles are just for the mid range, right?

 

no the pilots are just at and a little above idle, you haven really increased the flow when it's just idlein. So I would try that first, go back down to the 22.5's and it will probally fix your problem.

yes needleds are mainly for 1/4 to 3/4 throttle, but dont ignore they all work together. But like I said try the piolts first. And put the A/F back to 2 1/2 out.

 

I would change the pilots back but I had this problem before with the 22.5's. I thought that going bigger would help. Maybe I should put them back. Also should I raise the needles to get more fuel or lower them to get less? Wouldn't I need more?

 

usually stumbling and popping like you described is an indicator of to much fuel, so try playing with the needles after switching the pilots, or just lower the needles first since it is the easyiest to do.

 

Thanx for the help, I'll try that. Much appreciated.

 

What did you do with the air box lid?Any holes or is it closed?On my raptor I did the k@n filter trimed the flaps in the snorkel,left the top of the air box closed.On the exhaust I removed the spark arrestor ,drilled several holes in the plate inside the exhaust so its more of a straight threw air flow.Jetting 145/150 pilots25 2.5 turns out .I left the needles alone and it runs awsome.If you have holes in the lid experiment with duck tape close them and see what happenes.