Engine won't run unless enricher is pulled out

Discussion in 'Engine, Fuel and Exhaust' started by BigT, Nov 16, 2008.

  1. BigT

    BigT Member

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    One day I pulled into the garage and shut off the engine. I didn't turn the gas off right away and noticed gas running out the overflow hose. I know this is most likely the needle valve so I decided to rebuilt the carb ( original on this bike). Before I rebuilt the carb I started it up again just to see if it was still leaking. Now the engine won't run unless the enricher is pulled out. After it warms up I can push it in part way and it runs slower but rough. Pull it out and it runs good but fast. Push it all the way in and the engine stops. So I rebuilt the carb. New needle valve, new gaskets and O rings, new accelerator pump diaphram, new carb to manifold seal. cleaned it up good blew out all the jets. I did not take out the manifold. I put it back together. The carb is not leaking anymore but it still won't run unless the enricher is out. Anyone know what this might be?
     
  2. BigT

    BigT Member

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    I will check it out and let you know.
    Thanks
     
  3. BigT

    BigT Member

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    REED,
    The carburetor kit I purchased to rebuild my carb has two rubber seals in it. Are these the seals for the intake to the heads connection? Also what is the device that the vacumn hose at the top of the carb is connected to? Also could my problem have anything to do with the vacumn piston? The vacumn piston seems to be working OK. It moves freely and when I twist the throtle it moves up.
    Please advise,
    BigT
     
  4. dangerdan

    dangerdan Junior Member

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    That maybe a VOES (Vacuum operated electrical switch) It control timing. make sure it and all hoses/connectors are not leaking.

    See the Self Help: VOES Switch Explained - Harley Davidson Community

    Are you using SS or HD carb ???

    I have an SS carb and had the same issue. In my case I had to use spacers between the carb and engine. Without those spacers I was twisting the adjustment lever and causing the enrichervalve to bind.
     
  5. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    Yep. The black "rubber" seals are for the intake manifold to heads. You should have another between the carb and intake manifold. If you are taking the carb off again, replace all of those and make sure the intake manifold to heads is nicely secured. The fact that you are having to run with the enricher pulled out suggest it is too lean when pushed in like you have a leak on the intake side.

    Replace the vacuum hose to the VOES (if you have one). Don't need to go to HD for that, just get a bit from the auto parts store that will fit snug.

    I am assuming you have a Keihin CV carb. As long as the slider is free to move up and down, it is probably fine. When you have the carb off, take off the top cap (watch out for the spring and everything!) and look at the diaphram to make sure it looks good.

    Let us know how it works out.

    TQ
     
  6. glider

    glider Veteran Member

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    If the diaphragm was bad, it would idle without the enricher once warmed up but poop out when you twist the throttle.
    Sounds like the float bowl isn't getting fuel. If you have the vacuum operated fuel valve, remove the hose and pull some vacuum with another piece of hose and see if fuel flows. If no fuel the valve is bad, if fuel flows, check the needle and seat in the float bowl. May be necessary to drop the bowl to observe the flow.

    Check for this screw in the rear of the float bowl from the horn side between the cylinders. You can use this to see if there is fuel making it to the float bowl instead of dropping the bowl.

    [​IMG]
     
  7. BigT

    BigT Member

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    Yes, the carb is a Keihin (original one). I did replace the seal between the carb and the intake. and the bowl is full of gas (gas flow seems OK). I did not change the seals between the heads and intake because it looked like a hassle and I didn't think they were bad. I didn't take the top off the carb because the mechanic at the bike shop where I bought the kit said I didn't want to take a chance on screwing up the diaphram since they were another $40. So I didn't do it. This weekend I will try the either test. I have a solid feeling that this is where the problem is.
     
  8. BigT

    BigT Member

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    OK, I tried the ether test. I sprayed around the heads at the manifold and also where the carb attaches to the manifold, but I didn't notice any change in the RPM. Since I had the new seals I went ahead and installed them anyway hoping it would solve the problem but it didn't. As before, I can start the bike with the enricher out but as I push it in slowly the RPMs go down and and if I keep pushing it in the engine stops. It's like it's not getting any gas without the enricher. The carb bowl has gas in it. What ever is suppose to get the gas from the bowl to the engine is not working.
    I need some more ideas. I appreciate any suggestions.
     
  9. glider

    glider Veteran Member

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    It sounds like the low speed circuit in the carb isn't delivering any fuel to the engine. It may be necessary to remove it and check out that circuit. Take a look in this post for details.

    CV Carb Rejet Pics - Harley Davidson Community
     
  10. BigT

    BigT Member

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    I didn't mess with any of the adjustments when I rebuilt the carb. It will run if I throttle up then push in the enricher but it runs really rough and backfires.