Racing Idle

Discussion in 'Mechanics Garage' started by mnvfr, May 19, 2009.

  1. mnvfr

    mnvfr New Member

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    Hey Guys,

    I have a 3rd Gen VFR and have been experiencing problems with the idle racing. The problem seems temperature related as I've never experienced it during cooler riding. I first noticed the problem after a few hours of stop and go riding. We took a short 15 minute break and when I started it up, the rpm's shot to 4K and stuck there. I tried to adjust the manual idle screw down with no luck. The next morning, I started it up and it ran perfectly. This has happened to me three times all during warm days (70 deg plus). The temperature gauge was reading half way between cold and hot during this event. Anybody have any ideas?

    Thanks,

    Joe
     
  2. deepdish

    deepdish Banned

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    are your slides sticking?? remove and clean carbs float bowel off etc then reinstall.. carbs need to be cleaned every year if the bike sits up during the winter..:thumbsup:
     
  3. squirrelman

    squirrelman Member

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    high idle may be an intake air leak.

    is the bike running on all 4 cylinders 30 seconds after you start it ?? ?? touch each exhaust pipe to check, and, yes, you do need to kneel or bend way over to check rear cylinder headpipes.


    i'm thinkin not the carbs but loose or cracked carb mounting manifolds or sticking throttle cable . carb slides seldom or never stick in the up position. manifolds do harden up over time and may not seal proppa.

    {carbs normally need no cleaning if riders simply run the engine out of fuel by turning petcock to OFF, running until engine dies, then open float bowl drain screws BEFORE STORAGE ........}

    get a sharp phillips on each of the 8 clamps and tighten as necessary.

    if that doesn't help then a carb synch might cure it.
     
  4. mnvfr

    mnvfr New Member

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    Thanks guys for your prompt responses. Deepdish - there may be varnish in the carbs as this bike sat an entire year in the previous owner's garage. I've been running sea foam in the last few tanks of gas but haven't noticed a difference. I'm going to take a look at the carbs and mounting manifolds this weekend. I will let you know what I find. I've watched my brother bench synch carbs on his 78 cb 550. Can you do this on the VFRs or do you need a manometer? Squirrelman, there has been no evidence of the bike running on less than four cylinders but I will check next time I experience this problem. Thanks again guys for your advice. I'm sure there will be more questions to come.

    Joe
     
  5. squirrelman

    squirrelman Member

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    visual bench synch is fine and can get you close enough for further improvement.
     
    Last edited: Nov 11, 2011
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