Ok heres the deal i have a 2005 yfz 450 with a hmf bill ballance pro series pipe and head pipe and UM Performance aluminum air box with mesh screen and K&N airfilter. Im using a dyno jet kit also. This is what they call for. Needle clip on 5th notch 48 pilot jet and 160 main jet with air fuel screw at 1.5 turns and it sputters some thime near redline when in 3rd through 5th gear and some times back when i let off the throttle in 5th gear when in nuetral and i hit the throttle it will shoot flames out once in a while. I have tried the 155 jet that seems to lean and the 165 jet that seems to rich also i have tried the needle clip in the 4th notch with these jets. With there kit there is nothing in between 155 and 160 and 160 and 165. What im thinking is this kit is junk and i dont feel like driving 5hrs away for someone to hook it up on the dyno but I will if thats my last option. The 155 main jet runs better than the 160 and 165 but it is small than the stock jet at 158 and i dont want to burn up my engine. So can anyone tell me what is wrong or what different jet kit to order. oh by the way I live in Southern Wisconsin and i think that is around sea level but im for sure we are under 1000 ft. So any help would be great.

Thanks
Brian

 

, do everything exactly like they say, except you need to run a 148 or 150 out of the Raptor kit, you can order just those jets from dynojet, you will be happy with it, and those numbers are smaller than the stock jets numbers, but dynojet uses different measuring ways and so there numbers are different, you can not go by that, so tune it in with a 148, or 150 (your choice) and if you dont beleive it, go ride it for a little while and do a plug check!

 

Throw it away and get the NCQV needle and 165-180 mains, 45 and 48 pilot. Start with a 170, 45 pilot and needle on the 4 clip. Goto to YFZ central for more info if needed

 

Man that is exactly what I run , gytr kit , with a ncvq needle and a 170 main, with a 48 pilot, but you can make the dyno jet kit run good

 

ok i got it all figured out im running the 48 pilot 150 main and 5th clip on their needle and that works a hell of alot better not sputter and no flames out the pipe at all. Runs strong as heck too.

 

excellent

 

who all is using dyno jet jet kits? someone please tell me ur settings and if it hauls *****...mine halls ***, but it dont haul *****...i need some help, such as ur needle position, jet number and where ur located, im at 1100 feet in oklahoma

 

When you put a after market muffler on or an after market exhaust you lean out your fuel mixture. Normally when you put jet kits in you want to run slightly richer than what it was set at, you want to make sure to count the number of turns your mixture screw was at stock, and normally only go a quarter turn to one have turn richer.