87 VFR 700 Carb and Fuel Issues

Discussion in '1st & 2nd Generation 1983-1989' started by Coldfire117, Nov 18, 2018.

  1. Coldfire117

    Coldfire117 New Member

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    So, recently worked on carbs.

    Fuel is running, but right now bypassing the relay since it is dead.

    I got the bike to start, it idles and I let it warm up.

    Issues so far:
    • Pump is drawing fuel even though the fuel tank petcock is on OFF. There is enough fuel passing through to keep the motorcycle running and even revving.
    • If the petcock is set to ON while the bike is running, the carbs overflow and gasoline is released through the overflow tube. This kills the bike.
    I ordered a new fuel pump relay, so that will be fixed soon.

    But I need help with the issues above. This is the first time the bike ran and warmed up since 2015 - 2016. I was able to rev it up no issue, but I am concerned about how it is actually able to run even with the current issues.

    Any help is greatly appreciated!
     
  2. squirrelman

    squirrelman Member

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    overflowing fuel is from leaky float needles or incorrect float levels.
     
  3. Coldfire117

    Coldfire117 New Member

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    I'll definitely take the carbs apart again. I did not adjust the floats, I didn't think it would come back to haunt me. Luckily I know how to take it apart and put it back together no problem now.

    Even then, is it normal for the pump and system to work when the petcock is set to OFF?
     
  4. squirrelman

    squirrelman Member

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    probably a bad gasket in the petcock.
     
  5. Coldfire117

    Coldfire117 New Member

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    Thank you again, sorry to bother ya.

    I will update as I do the repairs this week!
     
  6. MFTIC

    MFTIC New Member

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    Yeah, what he said. I personally don't do float levels, LOL.
    Stupid question...how long you let the bike run with the petcock on OFF? There is a stupid amount of fuel in the system after the petcock and the bike will run a long time even under revs. LOL, i just did this and got bored so unhooked the line as I was trying to run the system dry. Still ran a long time. You probably knew all this....
     
  7. Coldfire117

    Coldfire117 New Member

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    So far, I let it run for about 10 minutes to warm up. I did this twice now, so 20 minutes total. I even rode it around the neighborhood today to test it. This has all been done with the petcock set to OFF. So yeah, there must be a lot of fuel in there, but I also know that there is some flow going through the pump. Might need to fix the petcock too.
     
  8. Diving Pete

    Diving Pete Insider

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    fix the petcock FIRST...
    Reason being in that:
    1. its easiest.
    2. you might not then need to go further - although I think you will)...

    If you have rebuilt the carbs then setting the floats correctly also makes a huge difference...
     
  9. Coldfire117

    Coldfire117 New Member

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    Currently about to fix petcock. Almost done with the floats!

    The bike ran, I was able to use it for a bit and enjoy it before the teardown.

    Will definitely update again!


    Sent from my iPhone using Tapatalk
     
    MFTIC likes this.
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