cant Get 06 450 to run right

[nillbag]

anybody out there have any advice for me on a jetting problem I have an 06 yz 450 and my fuel screw kept falling out Because I had to back it out so far so I changed My main jet to a 170 and my pilot jet from a #42 to a #45 It had helped it stop popping and it runs a bit better the only problem I am having is It has a very slight hesitation right when I hit the throttle it almost bogs for a second before it hits I am also running a FMF factory 4.1 exhaust sys. any advice would be greatly appreciated.

[CaptainKnobby]

Mine done the same thing when i put on a DRD full exaust then I pt in a #48 pilot and left #165 main in it and the put the the jet needle in the #5 clip position and it runs good now the fuel screw is at 2and1/4 turns out.

[StPeters21]

I'm running a 50 pilot jet/ 168 main/ NFLR needle. I have WB pro exhaust on a 06. I think Pro Circuit recomended a 48.

[yamahacrazy_310]

I got the 4.1 on my 06 and my jetting is 170 main 48 piolet and it runs fine.

[live4speed]

try going to the 48 pilot...i run a 170/48 in mine and its a hammer! i think my fuel screw is about 2 turns out.. maybe 2 1/2...

[yami racer]

I am running 48 pilot and 165 main in CT at sea level. Will go to 45 pilot in spring (wow soon) No hesitation. Also remember if this is your first four stroke you will need to learn how to roll the throttle rather than snap it open

[racegmc]

I am running the fmf jet kit in my 06 450f and it screams. I also have the 4.1 and uni filter