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While Ken is gone, I need your help....

Discussion in 'CV Performance' started by siffordd, Jul 26, 2013.

  1. siffordd

    siffordd New Member

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    You could go to this thread in the CVP Tuners Kit section and review my issues.

    "Good idle and lower RPM but hesitating over 3K RPM"

    But I will also paste some of the thread here to get your experienced feedback. Trying to get ready for my big trip next week and want to nail this down! Thanks in advance for your help!

    Siff

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    Good idle and lower RPM but hesitating over 3K RPM

    --------------------------------------------------------------------------------

    '04 Twin Cam with the 95 inch kit. Big Sucker intake kit and Bub Stealth 7 exhaust. Installed CV Stage 1 Tuner kit. 48 / 195 on the jets. I had also installed the new spring and carefully drilled the slide with the bit provided.

    Seems to idle well. EZ mixture screw has no effect that I can discern. No idle change screwed in or out. Confirmed that o-ring was in there.

    Runs well at lower throttle settings with little problem accelerating. Over 3000 RPM I get a hesitation or stumble. Another twist of the throttle gives a surge (good accelerator pump) but when it goes steady state anywhere over 3K , I get the hesitation / surging again.

    Got back and checked for leaks with propane. No effect so assume manifold seal is good. Wondering after a little reading on the forum if the slide surgery and spring might be the problem.

    Thoughts? Thanks for your insights.

    Siff

    ~~~~~~~~~~~~
    On a 95" with free flow air cleaner and exhaust you may want to move up to the 200 main jet. An exhaust leak at the head pipe flanges can also contribute to performance issues while at cruise speed.

    Sometimes on a Twin Cam (88 or 95) it is difficult to sense any change with the mixture screw because the ignition is compensating. Try lowering the idle to just above stall and keep turning the mixture inward blipping the throttle each turn until you can find where it hesitates. Then adjust outward by half a turn.

    Double check the needle jet (stainless nozzle) is installed correctly. Picture of this in the link below.
    Harley CV Carburetor - Tuning Issues and Troubleshooting
    __________________


    Enjoy the Ride!
    Ken
    Bike Talk Motorcycle Forum Admin
    CV Performance

    ~~~~~~~~~~~~~~~~~~~~~~
    OK Ken, so a follow-up. I went back and double checked everything and installed the 200 jet as recommended. When I was in there I went ahead and checked the needle jet and while it was in the right orientation, I'm convinced that it wasn't seated correctly that first time. When I put it all back together the jet stuck further into the venturi airflow area.

    I went ahead and took out the plugs and cleaned them to get a fresh sense of tuning. After warming up and trying to tweak the EZ Mix setting I rode it for a while. Entire thing ran much better with no hesitating or problem anywhere in the throttle setting. Seemed to run pretty good but was still wondering about the fine tuning.

    I rode for the week (~140 miles) and then pulled the plugs today to see how they looked. Dark and sooty looking. Suspect things are a little rich. I was careful not to overly use the enricher during the week.

    I would like a little direction on things to check. Looking at the forum my guess in order of things to check:

    Ensure enricher not binding or or stuck partially open
    Work with EZ on air mixture to try and lean it out (still fairly insensitive to setting)
    Go to a smaller jet?

    Anyway, your insights are welcome. I feel like I am ever so close.

    Thanks

    Siff
    Last edited: Jul 26, 2013
  2. HarleysLR

    HarleysLR Active Member

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    :rant: a little rant here:rant:
    You will read on here that some drill all the slides they have ever worked on.
    I have never drilled or cleaned up the hole in any slide and I have never had the kind of troubles that some say they have.
    What needle are you using?
    Did bike run good before you started messing with the carb?
    1.) If so go back to what you had and try one thing at a time.
    2.) Check to make sure all the piece are installed correctly.
    3.) If a new slide is out of the question I'd try putting the stock spring back in.
    4.) Check out ebay for a completely stock carb for parts.

    These are very good carbs and actually very easy to tune. Don't over think it.
  3. kenfuzed

    kenfuzed Administrator Staff Member

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    Hi Siff I'm still out of town but saw this message. It sounds like the only problem you're having is now a rich condition by the plug reading? You could try to dial the mixture in by 1/8th of a turn. I'm not familiar with those pipes but if they are not baffled that will contribute to a cruising speed hesitation. Drilling the slide with the included drill bit shouldn't be much concern since that is only 7/64 meant to clean up the slide, but worse case you could try the original spring to slow the slide action.



    Sent from my iPhone using Tapatalk
  4. siffordd

    siffordd New Member

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    Thanks for the rants and advice from all. I tweaked the jets and ran it again. I think I'm good but will be carrying the extra jets with me on my trip next week.

    I do appreciate the advice. As an engineer and a Tinkerer, I'm as likely to play with something to better understand it as much as anything. I now understand my carb better than I did before and feel comfortable tweaking it when I am at 8000 feet above sea level on a 95 degree day or when I am at home in Seattle on a 65 degree day.

    I still find the air mixture (EZ) to be a pretty subtle device. but will continue to see what difference it can make.

    Thanks for all the support.

    Siff

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