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2005 HD XL1200C, CVP CARB PROBLEMS "coughing"

Discussion in 'CVP Stage 1 Tuners Kit' started by ams2mac, Jul 18, 2012.

  1. ams2mac

    ams2mac New Member

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    I know this has been beat into the ground but I don't see anyone with the same problem as mine. "carb coughing" My bike is a 05 1200C, it has V&H short shot pips with an RSD air cleaner. I have just recently installed the CVP stage 1 kit. I follow the instruction to the “T”. The bike runs grate at idle and when you hammer on the throttle it gets up and moves with some authority. BUT when you’re running around 40 to 60 mph (4th or 5th gear) the bike will get this very small feeling of hesitation and then it will start the coughing. It will do this all day long. I have the EZ screw out right at 4 turns. The jetting was set to what the instruction stated. Before doing this, the bike had a SE air intake on it and it would cough but not that much. Please HELP!!!
    Last edited: Jul 18, 2012
    ams2mac, Jul 18, 2012
    #1
  3. kenfuzed

    kenfuzed Administrator Staff Member

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    Before getting into diagnostics can you tell me a few things about your bike and the installed kit?
    1) Is this a factory 1200 or did it start life as a 883?
    2) What size pilot and main jet did you install from our kit?
    3) Were any other parts replaced during the installation (gaskets, seals, etc)?
    4) Had the slide port been drilled prior to the installation? This can be checked by using the included drill bit as a gauge. If the off-center hole is larger than the bit then the port has been drilled to 1/8" or larger and will require replacement of the slide. If the supplied bit does not fit or just barely fits then the slide is fine.

    Having the mixture screw out 4 turns is reaching it's maximum which generally indicates the pilot jet is too small or there is a vacuum leak that the jetting/mixture is trying to compensate for.
    kenfuzed, Jul 18, 2012
    #2
  4. ams2mac

    ams2mac New Member

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    I just recently got this bike second hand. The bike has 19,000 miles on. It is an original 1200, I am not 100% on the size pilot and main jet I installed, it was what the instruction sheet recommended. I want to say it was 46 / 180. I will have to double check when I get home and look at the bike. I had to remove the rear exhaust pipe to install a new starter. I ran the bike after that and there was no changes to the run ability after that repair. The slide was a little in question when I removed it. The hole was stock size and so I drilled it with the supplied bit. On the back side of the slide there was very heavy wear marks on it, all most like gouges on the flat portions of the slide.
    Last edited: Jul 19, 2012
    ams2mac, Jul 18, 2012
    #3
  5. kenfuzed

    kenfuzed Administrator Staff Member

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    If the pilot jet used is the #46 you are already on the high end (rich) so the mixture screw should not need to be out 4 turns. How far inward can you turn the mixture screw before you start getting coughs/hesitation just off idle?

    I would start by checking for a vacuum leak around the intake manifold. The best test method is to use propane (unlit) and wave the end of the torch (emphasizing again, unlit!) around the manifold while the bike idles. Any drop in idle speed indicates a leak.
    kenfuzed, Jul 18, 2012
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  6. ams2mac

    ams2mac New Member

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    ok, I used the 46/185. I also ran up to the dealership and got a new slide and seal. I can turn the EZ knob in to just about seat before it cuts the bike off. Should I put the 45/180 in?
    ams2mac, Jul 18, 2012
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  7. kenfuzed

    kenfuzed Administrator Staff Member

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    Stick with either the 46/185 since you are running the V&H pipes and free flow air cleaner or drop the main jet down to the 180 if it feels sluggish. Adjust the EZ-just out around 1-3/4 turns and see if there is any hesitation when you blip the throttle or take off from a stop. If you get a hesitation adjust the screw out another 1/8th turn and repeat until you get a smooth (cough-free) response.
    kenfuzed, Jul 18, 2012
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  8. ams2mac

    ams2mac New Member

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    ok, I will give it a run now.
    ams2mac, Jul 18, 2012
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  9. ams2mac

    ams2mac New Member

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    Is it bad that I can turn the EZ screw in all the way with out the motor changing even the slightest. I just ran it 15 miles and still the same thing. No matter where I turn the screw
    Last edited: Jul 19, 2012
    ams2mac, Jul 18, 2012
    #8
  10. ams2mac

    ams2mac New Member

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    OK, what I have done tonight, I removed the carb, took the main / slow jets out and reinstalled them. I replaced the the slide, and the fuel accelerator diagram. Using a dental mirror and light I look inside the intake and could only see a portion of the MAP sensor rubber gasket. Removed the MAP and check gasket and reinstalled. I reset the EZ knob and put the carb back on the bike. I ran it in the drive way for 5 min. Turned the knob all the way in and the motor did not change pitch. With it in I bumped the throttle and it coughed right off the bat. I them backed it out 1 full turn and went for a ride. Every time the bike would acted up I pull over and turn it 1/8 until I reached 3 1/2 turn. I stopped and got gas and came home.
    ams2mac, Jul 18, 2012
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  11. ams2mac

    ams2mac New Member

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    Just performed VAC test, Check good around intake
    ams2mac, Jul 18, 2012
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  12. ams2mac

    ams2mac New Member

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    Is there any body out there, any one have a hint for me?
    ams2mac, Jul 21, 2012
    #11
  13. ams2mac

    ams2mac New Member

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    For the second time, it is a bad thing that I can turn the EZ knob all the way in and the bike does not cut off? I am asking for help.... PLEASE
    ams2mac, Jul 22, 2012
    #12
  14. kenfuzed

    kenfuzed Administrator Staff Member

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    Sorry several posts were lost on a few message threads here after a spammer inject a bunch of junk posts.

    On all the newer XL's and Twin Cam models it is common to not feel the idle drop when turning in the mixture screw. To better find the sweet spot I recommend starting with a lean setting around 1-3/4 turns out, ride and blip the throttle from an idle to see if there is a slight hesitation or cough. Adjust the mixture outward by 1/8th of a turn and blip again, repeating until you eliminate the hesitation. This should be the sweet spot.
    kenfuzed, Aug 5, 2012
    #13

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