2007 CRF80F jetting
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    Kiwi
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    2007 CRF80F jetting

    by Kiwi » Tue Jul 03, 2012 1:28 pm

    My son has outgrown his 2008 CRF70F so I think I may buy a 2007 CRF80F for him. I have looked through the jetting sections but did not see anything pertaining to a CRF80F.

    We almost always ride at Hungry Valley (Gorman, CA) that is located at about 3,500 feet altitude.

    Thus, does anyone know:

    1. What jetting should I run?
    2. Should I use a different needle (what Honda part number) ... and if so on what clip height?
    3. With new jetting and needle, how many turns out should the fuel screw be set?
    4. For 2007, the fuel screw is a D-style anti-tamper type. Is there a direct fit adjustable fuel screw to use (what Honda part number)?
    5. Any other simple mods for the CRF80F to improve power or handling?
    Last edited by Kiwi on Mon Jul 22, 2013 5:12 pm, edited 3 times in total.
    2007 CRF450X with modified airbox, Uni filter w/no backfire screen, NCVS needle on 4th, 172 main, CRFs fuel screw at 2, Boyesen QS3, stock smog, 450R cam, FMF Megabomb header, Pro Circuit T-4 muffler, Pro Taper Evo bars, AS suspension
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    Kiwi
    Posts: 363
    Joined: Thu Sep 25, 2008 12:22 pm

    by Kiwi » Tue Jul 03, 2012 8:13 pm

    OK, I just bought the CRF80F for my son. I fired it up and it has a massive bog at lower rpm when you give it significant throttle. After some careful feathering, it will gain rpm and then run OK (not great) at higher rpm. I checked the air filter (it's clean) and I checked the spark plug (it looks OK). Currently the bike is located in Los Angeles at a few hundred feet altitude and I'm guessing that it is a sign of being lean.

    Thus, please send any/all jetting/needle suggestions.

    Thank you,

    Management
    Last edited by Kiwi on Fri Jul 06, 2012 12:33 am, edited 2 times in total.
    2007 CRF450X with modified airbox, Uni filter w/no backfire screen, NCVS needle on 4th, 172 main, CRFs fuel screw at 2, Boyesen QS3, stock smog, 450R cam, FMF Megabomb header, Pro Circuit T-4 muffler, Pro Taper Evo bars, AS suspension
  • User avatar
    Kiwi
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    Joined: Thu Sep 25, 2008 12:22 pm

    by Kiwi » Thu Jul 05, 2012 1:16 pm

    Due to the massive overflow of replies to this subject I spent some quality time scouring the internet in search of the jetting answers. This is what I learned:

    1. Replace the stock non-adjustable-height needle with needle kit #16012-GN1-A41. Set clip height on second from the bottom.

    2. Replace stock #95 main jet with a #100 main jet (#99101-116-1000). However, the 100 main jet is no longer made/sold so I ordered a #98 main jet (#99102-GHB-0980).

    3. Leave the stock pilot jet (#35) alone.

    4. Replace the stock non-adjustable (via tamper resistant D head screw) with an adjustable air bleed screw (#16106-143-620). Set air bleed 1.5 turns out, then adjust per specific altitude/weather conditions.
    2007 CRF450X with modified airbox, Uni filter w/no backfire screen, NCVS needle on 4th, 172 main, CRFs fuel screw at 2, Boyesen QS3, stock smog, 450R cam, FMF Megabomb header, Pro Circuit T-4 muffler, Pro Taper Evo bars, AS suspension
  • Local Yokel
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    by Local Yokel » Fri Jul 27, 2012 6:54 pm

    Let us know how this turns out. But I'll bet your jets are dirty. Carb needs cleaned. Our 80's carb gets dirty regularly. I'm sure there is something to be gained with rejetting too. Though ours ran pretty nice right out of the box with factory jetting. But then again we are at 1,200 feet above sea level.
  • User avatar
    Kiwi
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    Joined: Thu Sep 25, 2008 12:22 pm

    by Kiwi » Sat Jul 28, 2012 8:43 am

    The first thing I did was to go through the carb and clean it out. It ran slightly better, but not great.

    I just installed the new jetting, adjustable air bleed and such and it is much better. While power is only slightly better, the throttle tip in and steady state is radically better.
    2007 CRF450X with modified airbox, Uni filter w/no backfire screen, NCVS needle on 4th, 172 main, CRFs fuel screw at 2, Boyesen QS3, stock smog, 450R cam, FMF Megabomb header, Pro Circuit T-4 muffler, Pro Taper Evo bars, AS suspension
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    Vee5
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    by Vee5 » Sat May 03, 2014 3:43 pm

    Just did this to an 2008 that I bought for my son recently. Spot on recommendation Kiwi- Thanks! Borderline criminal how crappy they have these bikes running new; The poor average guy will just live with it as is.
    Is it beer :30 yet?
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  • Kevin8520
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    Joined: Sat Dec 12, 2015 6:45 pm

    by Kevin8520 » Sat Dec 12, 2015 7:07 pm

    Kiwi,

    I know this thread is old, but I was looking for the adjustable air bleed screw 16106-143-620 you mention. That part number does not exist anywhere. Do you know of a different part number?


    Kiwi wrote:Due to the massive overflow of replies to this subject I spent some quality time scouring the internet in search of the jetting answers. This is what I learned:

    1. Replace the stock non-adjustable-height needle with needle kit #16012-GN1-A41. Set clip height on second from the bottom.

    2. Replace stock #95 main jet with a #100 main jet (#99101-116-1000). However, the 100 main jet is no longer made/sold so I ordered a #98 main jet (#99102-GHB-0980).

    3. Leave the stock pilot jet (#35) alone.

    4. Replace the stock non-adjustable (via tamper resistant D head screw) with an adjustable air bleed screw (#16106-143-620). Set air bleed 1.5 turns out, then adjust per specific altitude/weather conditions.

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