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  1. #1

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    syncing carbs/idle questions

    Hey guys,

    I was working with my carbs the other day and on taking them off noticed that the rear carb was slightly open more than the front one at closed throttle. So I'm looking to get my idle more stable, and that looks like the culprit, always been a lumpy 1300rpm.

    My main question is how do others do this? Do i need to back off the idle screw first? Will having the throttle cable off matter? Then I've also read people sync them full opened using the high speed bowl to line it up , is that the best way?

    thanks, excited to get it running better.
    Last edited by nickmm; 08-03-2013 at 06:00 PM.


  2. #2

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    I finally dug around in the Mikuni Manual again, found it. Which, if you didn't know, can be found here

    Just back out the idle stop screw, and hold both throttle plates closed, and adjust accordingly for closed plate position. Pretty easy.

    I still have a somewhat lumpy idle, not sure how its supposed to seem but it bounces at 1300rpm, its not really that smooth even at 1500. Not sure, but my lows are 85 set at 1 1/2 out, not much done to the motor either.

  3. #3
    flyin' the friendly skies airbornexp's Avatar
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    Quote Originally Posted by nickmm View Post
    I finally dug around in the Mikuni Manual again, found it. Which, if you didn't know, can be found here

    Just back out the idle stop screw, and hold both throttle plates closed, and adjust accordingly for closed plate position. Pretty easy.

    I still have a somewhat lumpy idle, not sure how its supposed to seem but it bounces at 1300rpm, its not really that smooth even at 1500. Not sure, but my lows are 85 set at 1 1/2 out, not much done to the motor either.
    that motor is kinda like that. if it idles well on its own with out some throttle your good. If you want post a video of it idling in the water on the trailer and can verify for sure its ok.

  4. #4

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    Sounds about consistent with this guys video. Runs alright at 1100-1200rpm on water, tested this morning. Just really burbly/bouncy. Tears it up after that, good 3k/4k cruise to wot, good idle-wot-idle-wot a few times in a row. I'd say I have it almost perfectly tuned. Running 6950rpms on my tiny tach in very light ripples this morning, no drop off. Pretty happy I guess. No GPS, just my speedo, not sure on speed, but probably barely 60 considering the prop is old/beat.

  5. #5
    flyin' the friendly skies airbornexp's Avatar
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    Yep that's about right....I would adjust your idle screw up a tad and call it good. You should be running 58-61 ish stock

  6. #6

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    stock w/choke delete and proks, jet kit. very happy with it, may gps next week when home, but cant complain about flawless running.

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