kellywellz

Member
Dec 16, 2008
4
0
I just bought a 04 yzf250 it has a fmf factory for full exhaust im not sure if the guy rejetted it after but if its idle or at low rpms when i give it gas it hessitates, will i need to reject it or can i just adjust the air/fuel screw? Also there is a dial on the bottom of the car that says "3" on it the owner said i could adjust at different altitudes. Let me know, thanks.
 

kellywellz

Member
Dec 16, 2008
4
0
heres a shot of my new bike, by the way this is my second post :)
 

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Matt90GT

Member
May 3, 2002
1,517
1
The YZF all have that bog. YOu have to rejet the bike even stock.

For the 03-05 bikes, this is the jetting that worked spot on for me. No bog, no hesitation.

JD blue needle at recommended clip
45 pilot
178 main
longer fuel screw adjusted about 1 7/8 turns out
#40 leak jet.
 

kellywellz

Member
Dec 16, 2008
4
0
so it is fine to run it how it is? I thought you were supose to rejet after getting a new exhaust to prevent running lean and causing harm to your engine? And adjusting the airscrew a lil wouldnt help at all?
 

kellywellz

Member
Dec 16, 2008
4
0
so it is fine to run it how it is? I thought you were supose to rejet after getting a new exhaust to prevent running lean and causing harm to your engine? And adjusting the airscrew a lil wouldnt help at all?
 
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