carb leaking fuel

7 replies to this topic
  • jevc

Posted September 26, 2005 - 07:26 AM


the bike runs good but when I stop fuel leaks out the bottom drain on the carberator. the screw is tight. the needle valve looks to be perfect and I cleaned everything real good. as per the manual I bent the tab on the float. I tryed this several times and when I finally got the leaking to stop the bike ran terrible so I bent the tab on the float back to straignt and it runs fine but leaks fuel again. any ideas? the instructions in the manual are a bit hard to undertand when it says to line up the float and the neelde valve. I dont rally understand what that means.

  • simon@vic

Posted September 26, 2005 - 07:55 AM


lower the fuel height 1mm from stock {by raising the float height}.

  • JTWR450

Posted September 26, 2005 - 07:55 AM


I have experienced this issue as well and found that when my bike is absolutely topped off with fuel it drips but when the tank has bit less full the dripping stops...weird.

  • toyota_mdt_tech

Posted September 26, 2005 - 08:50 AM


Make sure the fuel tank is vented. (not plugged) as the pressure from the heat allowing the fuel to expand can pressurize the fuel supply to the carb and the needle can submerge the float a bit and allow this dribble. If you think its a piece of debris in the needle/seat, the pressure from the float will hold it in place, turn the fuel off, run the bike till it starts to pop (or open the drain), then turn the fuel back on. The float level dropping down will release the needle letting go of the stuck debris and the fuel rushing in will wash the debris out. If none of these are the trouble, a new needle/seat is in order, assuming the float hasnt sunk. Some are brass (not sure of the WR) and can get holes and fill with fuel and sink.

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  • jevc

Posted September 26, 2005 - 09:13 AM


thanks for the advice. I will try all suggestions till I get it figured out. I hadnt thought of the fuel tank vent but you may have something there. This problem started at the same time I put on an IMS tank. I will check tomorrow and see if it vents.

  • bg10459

Posted September 26, 2005 - 02:11 PM


This problem was posted a couple of times before. Answer both times was float height.

  • jevc

Posted September 27, 2005 - 09:02 PM


I think i have it narrowed down to the needle valve. I looks to be in perfect shape but maybe the rubber shrank or something. I left the carb on the bike and just took the bowl off the bottom.I adjusted the tab on the float so the fuel shuts off just as the float goes past level with the carb housing. there is still a small amount of gas that drips by even when I raise the float up higher. I think this has got to be the needle valve so i ordered one and will install when it comes in. I know this may be confusing but I hope someone has an idea of what I am talking about and may have onother idea

  • simon@vic

Posted September 27, 2005 - 09:49 PM


the carb should be off the bike upside down on 30 degree angle. enough that the tab in on the "needle pin" but not so much it compresses the little sping...........


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