xr/crf 100 jetting questions
  • rocketman
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    xr/crf 100 jetting questions

    by rocketman » Thu Aug 09, 2007 1:25 pm

    At one time I thought there was a link to a site that had carburetor diagrams and tech tips. Any way my sons 2003 xr100 loaded up the piolet screw and started running very poorly. we pulled the card apart and Thoroughly cleaned it out. The piolet screw was black and sooty at the end and the spark pluck was black with soot. We put it together and it runs good again but i am thinking i am off a little in the jetting, it runs good up top but almost feels lean on the bottom (off idle when you grab a handful). Here is what i got. Any input would be great! I know we need an aftermarket air filter!
    2003 xr100
    chm full exhaust
    102.5 main jet
    38 pilot jet
    needle moved up one(clip down one)
    air box opened up 5-1"vent holes with filter
    stock air filter
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    zak13
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    by zak13 » Sat Aug 18, 2007 2:48 pm

    where did you put the vent holes im thinking of doing it but dont know where i would put them of course there are the obvious areas but im thinking wheres the best place to put them
    sellin my xr100
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  • rocketman
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    by rocketman » Mon Aug 20, 2007 12:19 pm

    I bought the 6 pack of 1" vents from this site,i drilled three holes in the top of the box in front of the snorkel and one on each side toward the rear of the airbox(in the corner), the side covers just hide the holes. i have not removed the snorkel because it appears to be about the same size hole? i might still remove the snorkel.
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    zak13
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    by zak13 » Mon Aug 20, 2007 1:35 pm

    okay i was thinking of drilling 4 holes on the left side and do as many as i can on the top then find some where else but do remove the snorkel and under neath the air box theres a small tube that attatches to the air box its a vent tube remove that also its not much but its something
    sellin my xr100
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  • rocketman
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    by rocketman » Mon Aug 20, 2007 5:05 pm

    it seems that most people on this site recommend remove the snorkel but i have not tried this yet. Just be sure your filter is good!!!
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    zak13
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    by zak13 » Tue Aug 21, 2007 8:18 am

    i pulled the snorkel its not much diffrence but ill do anything to get more power out of this bike
    sellin my xr100
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    mustang
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    by mustang » Tue Aug 21, 2007 9:49 am

    feeding more air to the airbox won't do much if the exhaust side is still corked up . everything needs to happen equally , ie. more air in needs more air out and richer carb settings to all work in conjunction . :shock:

    and on some machines the amount of air flow coming from the air box is already good enuff , because the cylinder head is what will determine the absolute maximum of air that can flow thru it .


    to put it simply if you have a passage way in your head of a 1/2 inch diameter and you feed it air with a 1 inch diameter hole you are gaining nothing because the head is the restriction , understand?
    c-ya****mustang Image
  • rocketman
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    by rocketman » Tue Aug 21, 2007 10:00 am

    what mods have you done to this bike? Performance only! not suspension, bars etc.. just motor changes....
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    Billys2006CRF100F
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    by Billys2006CRF100F » Wed Aug 22, 2007 10:41 am

    I opened up my airbox and removed the bike fire screen at the same time as I put on an aftermarket exhaust. Anytime you alter the intake or exhaust you must rejet to get the most out of your bike and to ensure it's running properly. Look at my garage photos to see what I did to the airbox.
    Click on my GARAGE link to see pictures and modifications that I've done to my CRF100F.
  • rocketman
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    by rocketman » Wed Aug 22, 2007 11:54 am

    i have seen billys bike (looking good by the way) good job dad! littleboy was trying to get better performance so i was looking to see what he had/hadn't done.
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    Billys2006CRF100F
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    by Billys2006CRF100F » Wed Aug 22, 2007 1:17 pm

    rocketman wrote:i have seen billys bike (looking good by the way) good job dad! littleboy was trying to get better performance so i was looking to see what he had/hadn't done.


    Cool. Thanks for the compliment. :D
    Click on my GARAGE link to see pictures and modifications that I've done to my CRF100F.
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    zak13
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    by zak13 » Fri Aug 24, 2007 8:51 pm

    rocketman wrote:i have seen billys bike (looking good by the way) good job dad! littleboy was trying to get better performance so i was looking to see what he had/hadn't done.

    lets see ive removed the snorkel removed the back fire screens and installed a uni filter then i turned my fuel screw to 1.75-2 turns out then i removed my whole exhaust insert no 1 knows what im saying when i explain this so heres a pic
    Image
    and this is my xr100r its just a photoshop pic and i dont feel like uploading the real pic bec it takes too long
    sellin my xr100
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  • Asmith
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    by Asmith » Fri Aug 24, 2007 8:54 pm

    Zak,

    your bike isn't really green is it???? :shock:
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    zak13
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    by zak13 » Fri Aug 24, 2007 8:57 pm

    ~ wrote:Zak,

    your bike isn't really green is it???? :shock:

    no its a photoshop pic and i dont feel like uploading the orig pic but i will just to show you hd
    sellin my xr100
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    zak13
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    by zak13 » Fri Aug 24, 2007 9:00 pm

    beforeImage
    after Image
    sellin my xr100
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