2001 Rm 250 Jetting

Discussion in '2-Stroke Discussion' started by ZOOK250, Oct 5, 2001.



  1. ZOOK250

    ZOOK250 Rookie DRN Member

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    when i bought the bike it was winter , there were no test done at that time in any magazines. my question is , what would be ball park jetting on this bike. 1000 ft above sea level,right now the temperature is between 5 celsius to 17 when we ride. canada eh.needle is in the center position. pilot is a 52. i installed an fmf sst, jetted it down to a 158 for sumer, came originally with a 168!!!. compared to my buddies yz , my bike feels totally less responsive. it doesnt feel like it will rev out on any track , however i can still pull holeshots with it. any thing else other than porting to make improvement for this model? even with its short comings the bike isnt all that bad.

  2. ZOOK250

    ZOOK250 Rookie DRN Member

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    jetting rm 250 2001

    5 degrees celcius is 41
    17 " " 63 degrees farenheit.
    didnt have my calculator when i posted original message.
  3. MN KDXer

    MN KDXer Registered

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    You will want to run a 48 pilot and put the needle in the #2 (from top of needle) position. The 158 main is about right for 55-80 degree temps. Note that you can swap both jets thru the bottom drain plug.

    I bought a Bills Pipe and Boyesen reeds for mine, and it helped a LOT with the top end revs and better mid range transistion. The taller (RM125) seat foam is a nice touch, too, if you're a taller person. Otherwise, I raced my 01 RM250 all season with pretty much good results.
  4. Chief

    Chief Subscriber Damn Yankees

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    More Ideas

    Zook,

    The fuel is a big issue with this bike. I wasn't happy with the way it ran on pump gas and have been told a good race fuel like vpc12 would make a big difference. Right now I'm having work done to lower the compression, so I probably won't be going the race gas route myself.


    MN KDXer, do you remember what kind of Boyeson Reeds you installed?


    Joe Chief
  5. Mike Fallon

    Mike Fallon Rookie DRN Member

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    01 rm250

    i went to c12 race fuel i could not get it to run pump gas iam at 155 main one up on the clip two down on the pilot and had the head done i have a sst fmf pipe Boyesen rad valve and a dynatec ignition system. it really runs good:p now
  6. Chief

    Chief Subscriber Damn Yankees

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    Mike,


    Thanks. Good to hear from people who have had positive results with the same bike.


    Joe Chief
  7. MN KDXer

    MN KDXer Registered

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    Chief,
    I installed the less pricey Boyesen reeds (power?). I talked to Boyesen tech dept, and they said the lower buck reeds were better for boosting the low and mid, and the Pro reeds were more for higher end durability. (at least, that's what I "think" I remember them telling me.) Whatever the actual details, those reeds seemed to be the best idea for me to boost the lower end power.

    From what I recall, the reeds added some top end over-rev. Not really more peak hp, but just added an extension to the powerband for those times when wringing it out a little more seems like the thing to do. :cool:
  8. RM_guy

    RM_guy Scared of DirtWeek<BR>Club ********* Damn Yankees

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    I had Eric Gorr port my engine for Mo power everywhere. It made a huge difference throughout the power band. There is more bottom and more over rev but the best part is the smooth transition from bottom all the way to the top. It’s like a tractor.

    I’m using stock reeds and pipe with Sunoco 94 octane pump gas. My jetting is 160 main (soon to be 158 due to some spooge), stock needle 2nd clip from top, stock power jet, 48 pilot, sir screw 1.75 turns out.

    I’d recommend Eric’s work before trying any aftermarket parts. It’s well worth the $120 ($110 with the DRN discount) and lots cheaper than pipe, silencer, reeds etc.
  9. ZOOK250

    ZOOK250 Rookie DRN Member

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    thanks for the help.i'll try them out next weekend.
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