Put on a fmf powercore 4 for my raptor.Removed the snorkle still using stock air filter, so do i have to rejet? If so anybody running same setup what size jets are you using? any info will help!!! thanks!!!!

 

I re-jetted my 02' raptor and still used stock air filter. I went up two jet sizes and it runs like a champ. I have not removed my snorkle. Will that improve the air flow??

 

Guardog,

Yes most definatly remove the snorkel, and yes it will improve the airflow. If you don't like the Idea of removing the snorkel at least take it off and cut out the flaps inside of the end where it connects to the lid. Very restrictive.

 

I have the FMF 4 and did not re-jet - runs good at sea-level (Glamis). Everything else is stock (except removed flaps in snorkel). It does not act lean (and plug looks good) but a slightly larger jet might be safer when it gets hotter outside. I plan to add the pro-flow foam air cleaner and jet kit soon.

Question: The FMF does not seal good to the stock headpipe - I get a wet, black soot spit before the pipe gets warm and seals - makes a mess. It's from condensation. Anybody else ?? Any solutions ?? FMF doesnt have much to say about it.

 

I removed the snorkel before riding today and it made a world of difference. The only thing I can say is... WOW

 

Gaurd dog what size jets are you using?

 

I'm not exactly sure what size they are because the mechanic at my local yamaha shop installed it for me. He said that it was two sizes up from the original jet. I can ask him when I see him next time. Whatever he did, it made the world of difference. I was also informed to remove my snorkel today. I did that and it really helped out also. If you have not done so, I would removes the snorkel after you re-jet. I now have to pick up a K&N filter with outerwear, because I don't like having the stock filter exposed to the elements without the outerwear on.

 

Stock jets are 140 left carb 145 right carb. These are KEIHIN jets at least in my Raptor. If they went up 2 sizes I would guess you now have 150 left 155 right. I have bought myself a whole selection to play with ranging from the 140 stock all the way to 175. 2-5 increments at a time. They are only 3 bucks each. Never bought a dyno jet kit. Don't realy see the need.

 

140 to 145 is considered 2 sizes. One size is equal to .025

 

there is a need for the dyno jet kit .....


It comes with needles witch are a major factor in how you raptor will run ......the needles that dyno jet suplies are much differant from stock !!!