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'99 R1 Fueling issues

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  • '99 R1 Fueling issues

    Hey guys and gals,

    (See previous thread, ) After checking that the R1 motor could freely turn, changing the plugs (checking for spark) and putting the airbox and tank back on, I've found that there is a fueling issue.

    I've checked the fuel pump and there is definitely fuel coming out on the output side of the pump. The pump appears okay as there is enough pressure on the output. From this point on I would only be guessing. I'm making the assumption that its not a stuck float, as there's too much pressure in the fuel line (surely the float would unstick itself at that pressure). I thought it may be blocked jets, but all of them blocked? The "blockage" is enough to stop the fuel pump from turning.

    Any help is much appreciated

    (Fuel flows up to this point)

    "Always out-numbered, never out-gunned"

  • #2
    The floats usually work against the pump to close the fuel bowl inlet so if the floats were stuck you would be getting way too much fuel and the bike would be running like crap if at all. Just to clarify you are getting no fuel and its not starting? you are getting heaps of fuel and its not starting? its starting but the throttle response just isn't there and you've got to hold it flat to kinda get it to run? Are the plugs wet from fuel after cranking, indicating that maybe exccesive fuel is getting to the cylinders, have you tried some neat fuel down the spark plug holes? admittedly not very practicle on a modern inline for or some start ya bastard down the carbs. If it fires on ethier of these then the motor is obiusly not getting fuel.

    Try dropping the nut at the bottom of one of the float bowls and see if fuel come out maybe fire up the fuel pump at the same time and see if you have a countious flow. Assuming they are CV carbs as fitted to most inline fours might be worth looking into the vacum setup seeing if any fluild/blockage is in there from been upside down. :shrug:
    Harvey community radio has a motorcycling show listen over the web here ,Facebook here yes I am the goose that hosts it.


    • #3
      Once the fuel bowls fill, the floats close the needle valves, and you have no flow.
      You sure there is a fuel problem?
      Being an Australian is not an excuse for being dumb and racist.


      • #4
        Darkfibre: Definitely a fueling issue. If the pump is pushing against something and as a result can't turn, I'd say there's something wrong

        Nero Diablo: Sorry mate, should have clarified. No fuel is entering the cylinders. I'll empty the bowls next time I'm at the bike and see what falls out.

        "Always out-numbered, never out-gunned"


        • #5
          Not going to dispute that you have a fuel issue, but once the float bowls are full the floats close off. If you keep pumping fuel, where do you expect it to go?
          If it was fuel injected the pump flows constantly at a regulated pressure, with excess fuel returning to the tank. This system does not have a return to the tank, so the flow must stop when there is no demand.
          Being an Australian is not an excuse for being dumb and racist.