but trust me guys, I have been reading for a long time, but what I am about to ask does not apply to what I have found by searching this site.

ok here is my question.
I have a 2003 raptor with FMF pipe ( I know but that is all what I found in my country) K&N filter along with some air box mods (Trimed snorkel, and four of those white brothers liitle filters that you placed aftere drilling a hole to the lid) that's all.

now my question is, I have jetted the raptor to 150/155 and clip on the 3rd notch, but that did not work well cause it was some sortta back-firing at WOT while cimbing a sandy hill. so I changed to the next jet up (155/160) but that seemed to make the bike slower, so I went back to the old set up but put the clip on the fourth notch. that did help a bit, but for some reasons the damn thing is still slow, well not that slow, but not any faster than a bone stock raptor. should I take the lid, and if I do so, what size jets should I use? and why my bike not any faster than stock ones? with my set up do u guys think i am running lean or rich. I am at a sea level, and the weather here is too damn hot, (80s and higher sometimes) oh by the way, I am from the United Arab Emirates.

thanks a lot guys

 

maybe you need to change your pilot jets...just my guess..

 

Its that stupid lid and snorkle...get rid of them.
Mine never ran right until it got enough air...even if you don't believe be just for craps and laughs place the 4 rear clips under the airbox lid and the front 2 cliped in place(like normal) to hold the af in place...give it a run.

 

Ok I will take the lid off. but how much bigger of a jet I should get? I am now at 150/155 on 4th clip, should I go to 155/160, or even more than that. I know I can just try both, but I would like a base line to start with, I really hate replacing jets on the damn thing. I mean for the rest of you guys jetting after taking the lid off, how much bigger do you guys go with leaving everything else the same?


help me guys please

thanks

 

160/165 clips on the 3rd groove and about 3 turns out on the idle mix screws.