gas boiling in gas tank

Discussion in 'Engine, Fuel and Exhaust' started by just4u, Sep 4, 2009.

  1. just4u

    just4u Banned

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    I was changing Power commander III map fuel values on my 06 FLSTC in the Garage. After turning the bike off and when into the house for about 5-10 minutes, I returned to the bike to see and hear the gas boiling in the tank. I removed the gas cap and the pressure blew off the cap. the engine was ideling fro about 10-15 minutes,so I could try a few different maps. these PCM fuel maps were good maps, the values were just a little different from each other. but not much. I've never heard of gas boiling in side a motorcycle gas tank before. has anybody else? I asked the Harley dealer service personal and They say they have never heard of this either.
     
  2. joe1984

    joe1984 Member

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    if gas got to the point of boiling it would have caused a flash up... if the fuel tank was low on fuel it could have bein just pressure.....
     
  3. just4u

    just4u Banned

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    the tank was half full. I went for a 80 mile cruise today and the engine runs great.
     
  4. STEVE07

    STEVE07 Well-Known Member Staff Member Super Moderators

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    Hot day,hot engine,no air getting to it and a plugged vent in the gas cap would be my guess.I think you heard the sounds of pressure building in the tank.While you are at it check the overflow tube on the tank and make sure it isn't restricted as well.
     
  5. vtbikers

    vtbikers Active Member

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    I agree check the vent.
     
  6. just4u

    just4u Banned

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    Hello all , My gas tank boiling was very werd, I changed my power commander one more time friday and did not have the gas in the tank boil. I did a compression test. It's the same as it was before. 135 front,130 rear. the vent is clear.
    I laso went for a test mini road trip 180 miles, Had some fun playing wuith a couple of honda race bikes at 95 mph. the bike ran Great. I'm baffled why my gas boiled while preforming map changes in the garage. the only thing I can figger is I made the changes while the bike was running. This is the only time I've done this. I always make the changes an then start the bike to send new map.
     
    Last edited: Sep 7, 2009
  7. just4u

    just4u Banned

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    I think the gas boiling was from changing the map values while the bike was at a an idle. the next map value change was made before the engine was running and the gas did not boil. the newest compression test 135 front,130 rear today was done after a 180 mile run, Had some fun playing wuith a couple of honda race bikes at 95 mph. the bike ran Great. I think the past map change went threw a lean spell, it's the only thig that makes sence. what do you think? anyone thank you.
     
  8. just4u

    just4u Banned

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    The gas boiling is in the past, I guess it does not matter now, the bike runs great with the newest Power commander down load. Hopfully this does not happen to anyone else. Change the map settings then start the engine and send the new map. Do not play with the settings while the engine is Idleing with out a fan blowing on the engine. :) MY Black Pearl is the meaning of Freedom. Savy ?