Is it carb, intake, sensor, I'm baffled

Discussion in 'Engine, Fuel and Exhaust' started by softailhog, Aug 21, 2009.

  1. softailhog

    softailhog Active Member

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    I'm a new member so please excuse my request for help but I'm baffled.
    I have a 2002 Heritage with stock exhaust (rare, I know), stock carb, completely stock engine. When I barely crack the throttle (like coming out of
    a corner) the bike sputters. It started out only doing it when cold, now does it all the time. Sometimes it will even cough when cruising at about 50mph but again only when the throttle is barely opened. At highway speed the bike runs great. Plugs looked good, I changed them. Other things I have done:
    1. checked plug wires with meter, OK
    2. pulled carb and competely went through, cleaned, inspected all jets and passages, checked float level. It was incredibly clean for 48k miles.
    3. sprayed WD40 around intake and carb gasket, no leak found
    4. replaced MAP sensor
    5. checked CKP sensor
    6. checked leads to both sensors for continuity
    7. checked battery voltage, battery is up
    8. washed and serviced air cleaner

    I tried to pull a code from the ICM by jumpering pins 1-2 on the datalink connector but only got one sequence of 12 flashes repeated over and over.

    I have never gotten a check engine light and the bike otherwise seems to run normal. What am I overlooking here? Any help is greatly appreciated!!
     
  2. glider

    glider Veteran Member

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    More than likely a re jet would take care of the problem. Up the size of the low jet one size and it should help.
     
  3. softailhog

    softailhog Active Member

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    Glider, thanks for your reply. Stock on the low jet is 45, what's the next step up?
     
  4. glider

    glider Veteran Member

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    #46 is the next size.


    The #46 jet is hard to find , here's a link if you need it..... #46 pilot jet
     
    Last edited: Aug 21, 2009
  5. softailhog

    softailhog Active Member

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    Called my local aftermarket shop, they have the #46 in stock. Thanks again Glider,
    you are the man!
     
  6. 00BUCKSHOT

    00BUCKSHOT Junior Member

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    glider is dead on (once again) i had the same problem jetting fixed my problem
     
  7. softailhog

    softailhog Active Member

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    An update: I installed the #46 jet and the hiccups went away. Rode about 350 miles over the weekend, gas mileage is still good (45mpg) and the performance is better. Amazing that a part so small can make them run good or so bad! Thanks for the help.
     
  8. glider

    glider Veteran Member

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    Awesome! Glad it solved the hiccups.:D

    Next step...


    Quick and easy way of testing the main jet size.

    Run the bike through the gears into third gear and run third up to 60-70 MPH full throttle, then chop the throttle about 1/8 to 1/4 back and see if the bike either surges ahead or stumbles then recovers.

    If it surges ahead, your jetting is lean
    If it stumbles and recovers , your jetting is rich
    If it makes no difference, you're pretty close.
     
  9. softailhog

    softailhog Active Member

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    Glider, I will check that next, thanks!