RM 250 jetting?

mx510
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mx510
Edited Date/Time 7/11/2012 4:17pm
I just picked a 2002 RM 250. The thing is running really rich and I am curious if anyone has one and has already got the jetting dialed for it. I was hoping to be able to get some jetting specs and just copy it and put in my scooter. I live in Washington and most of my riding is done at or near sea level and between 45-75 degrees outside. Thanks.
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mx5471
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mx5471 12/9/2011 2:48pm
12/9/2011 2:48pm
Stock jetting should work fine unless there are mods to the motor.
mag23
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mag23 12/9/2011 7:20pm
12/9/2011 7:20pm
if it's rich on top, easy, just drop the main jet one size. If it's blubbery and doesn't run real clean down low, reduce the pilot one and drop the needle a position. Fine tune with the airscrew. The bike will definitely run lean at 45 degrees, if jetted properly for 75 degrees. Run good fuel... not straight pump. Maybe 50/50 race gas/pump gas. Suzukis have been notoriously rich with stock jetting.
CamP
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CamP 12/10/2011 8:15am
12/10/2011 8:15am
I've always had good luck with Pro Circuit's recommended jetting. For the '02 RM250, they recommend:

162 main (165 stock), 48 pilot (55 stock), STD needle @ 2ND clip, AS @ 2 turns out.
Digger29
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Digger29 12/17/2011 3:32pm
12/17/2011 3:32pm Edited Date/Time 12/17/2011 3:34pm
I have a 45 pilot & a special needle which I can get you the number for if you need & it definitely cleans up the richness in middle & a 168 main & the air screw at 2 turns out & it starts first kick every time & runs perfect from bottom to top.What is done to your motor & what pipe & silencer combo are you running & do you race pump gas or race gas & at what ratio?

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mx510
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mx510 12/18/2011 7:30pm
12/18/2011 7:30pm
Digger29 wrote:
I have a 45 pilot & a special needle which I can get you the number for if you need & it definitely cleans up the...
I have a 45 pilot & a special needle which I can get you the number for if you need & it definitely cleans up the richness in middle & a 168 main & the air screw at 2 turns out & it starts first kick every time & runs perfect from bottom to top.What is done to your motor & what pipe & silencer combo are you running & do you race pump gas or race gas & at what ratio?
Stock motor with Pro Circuit pipe and silencer. I run straight pump gas at 40:1.
mxracer47y
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mxracer47y 7/11/2012 4:17pm
7/11/2012 4:17pm
Digger29 wrote:
I have a 45 pilot & a special needle which I can get you the number for if you need & it definitely cleans up the...
I have a 45 pilot & a special needle which I can get you the number for if you need & it definitely cleans up the richness in middle & a 168 main & the air screw at 2 turns out & it starts first kick every time & runs perfect from bottom to top.What is done to your motor & what pipe & silencer combo are you running & do you race pump gas or race gas & at what ratio?
Digger what kind of needle are you running I have a 2004 rm 250 that I'm rebuilding , they guy I bought it from said bills pipe ported and polished the cylinder and I'm also running a pc pipe and pc 304 silencer not the shorty silencer with 50/50 c12 an pump gas also have v force 3 reeds I have a 165 main in it now with a 45 pilot air screw 1 1/2 turns out basically followed pcs jetting but still feels funky also my idle screw is all the way in and it doesn't idle quiet high enough for me do you have any advice btw I live in western mass in the Pittsfield area so I believe we are at a similar altitude Thanks Adam
Gman93
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Gman93 7/13/2017 12:03pm
7/13/2017 12:03pm
Digger29 wrote:
I have a 45 pilot & a special needle which I can get you the number for if you need & it definitely cleans up the...
I have a 45 pilot & a special needle which I can get you the number for if you need & it definitely cleans up the richness in middle & a 168 main & the air screw at 2 turns out & it starts first kick every time & runs perfect from bottom to top.What is done to your motor & what pipe & silencer combo are you running & do you race pump gas or race gas & at what ratio?
mxracer47y wrote:
Digger what kind of needle are you running I have a 2004 rm 250 that I'm rebuilding , they guy I bought it from said bills...
Digger what kind of needle are you running I have a 2004 rm 250 that I'm rebuilding , they guy I bought it from said bills pipe ported and polished the cylinder and I'm also running a pc pipe and pc 304 silencer not the shorty silencer with 50/50 c12 an pump gas also have v force 3 reeds I have a 165 main in it now with a 45 pilot air screw 1 1/2 turns out basically followed pcs jetting but still feels funky also my idle screw is all the way in and it doesn't idle quiet high enough for me do you have any advice btw I live in western mass in the Pittsfield area so I believe we are at a similar altitude Thanks Adam
Hey Digger,
Same year Zook and same issues ! Did you ever fix the idle and slight richness ?

Thanks, Greg

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