I am wondering what pilot and main jets I should be running in my raptor? The problem I am having is that the header pipe is glowing red at low to mediun throttle and a lot of back firing from full throttle to no throttle. It has stock pilot jets and 158/160 mains ,I'm running a gradon full exhaust system,and a single pro flow k&n filter. also my choke has recently quit working, could this be a cloged pilot jet?

 

I think you need to bump up your pilots and what is you altitude??

 

Need to know:
1) Using the airbox lid, trimmed snorkle, no snorkle
2) Mikuni jets
3) How many turns out on the mixture screws
4) Stock needles, what groove is the clip on

 

thanks for your reply i'm not sure right off hand but i ride in phx,az and in glamis sand dunes.

 

I am using Mikuni Jets, I have no air box lid, but I am using a sand sox if that makes a difference. I am running dyno jet needles on the third clip or middle. and I am not sure about what idle screw you are referring to.

 

I have the exact same thing happening with my raptor. Headers glowing red. Is this bad?

 

Glowing headers is normal if you let it sit idling for a few minutes. Sparkless check your mixture screws they should be at least 3 turns out. If you can't get rid of the popping turning the screws out than you may want to try a 25 pilot jet. 155/160 or 160/165 mains should be about right maybe even 165/170 area with that pipe at sealevel to 3000'.