81 Shovel Starts and Stops

Discussion in 'Engine, Fuel and Exhaust' started by sduquette, Jun 4, 2008.

  1. sduquette

    sduquette Member

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    Hi All,
    This is the first forum I've joined. (Except the one I have to be in at work).
    I apologize in advance for anything wrong I've done or will do. I've had an 81 Shovel for 6 or 7 years that always ran great.

    However I developed a weird (Carb? ) problem last year. I have been just too busy to deal with it until now. The bike will start and idle for as long as I care to stand and watch it. But if I try to ride it, it'll go far 1/4 mile or so, then start to sputter and die. If I pull the choke out, it will go for a bit then start to die again. Then putting the choke back in keeps it going a bit more. So this constant fooling with the choke will sometime keep me going indefinitely (although annoying). But sometimes it just dies. If I sit there for a few minutes, it'l start right up and we play the game all over again.
    I've rebuilt the carb (twice just for fun), replaced the internal gas tank and external fuel filters. i am stumped. It sure seems like a fuel problem to me. But could it be electrical, and when something cools down its Ok again?
    Any ideas would be greatly appreciated.
    Steve
     
  2. glider

    glider Veteran Member

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    What if anything did you find in the fuel system when you had it apart. Was there water that usually people can't see when they work on the fuel system or sediment in there?

    Best bet is to check for ignition and spark at the time it happens and narrow it down to fuel or ignition and go from there.

    It sounds like a fuel system problem to me and you mention an internal and external fuel filter, that could be the problem with insufficient fuel flow to the engine, one or the other will work fine but not both.

    Welcome to the forum.
     
  3. Fisher

    Fisher Account Removed

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    I'd ditch the external fuel filter and see what happens.I bet it has insufficient flow from your description.
     
  4. sduquette

    sduquette Member

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    Glider and Fisher,
    Thanks for the responses!
    I didn't see any water in the tank when I replaced the filter, but there was some sediment. I ran some fresh gas through it before putting the new filter in.
    I'll try losing the external filter and quickly checking for spark in the next day or two. As soon as it stops raining. (Yes, fair weather rider, unless mother nature catches me off guard. Too old for that tough guy stuff).
     
  5. Doc 1

    Doc 1 Member

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    Steve the next time it wants to die open the gas cap....if you hear a hissing noise replace the cap....the vent is not working and the fuel will not flow to the float bowl fast enough to replenish what you are using, when you sit for a min or two the bowl fills.
     
  6. sduquette

    sduquette Member

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    Hi All,
    Went out to try some of the suggestions you've made. I removed the external fuel filter and tried removing the gas cap when it started acting up. No Help. I checked for spark just as it died and it looked OK. It seems to be worsening in that it now acts up just sitting and idling. I looked back to the carb, and with the air filter off i noticed that as its starting to die, and I start pumping the throttle, there are no (or wimpy)squirts of gas that you usually see from the accelerator pump. So now im convinced that the carb isn't getting gas into it fast enough. As I started to remove it yet again to see if the float maybe needs some adjustment, I noticed that the black plastic elbow that the gas line connects to was slowly weeping gas. Upon closer inspection it appears to have a hairline crack in it causing this leak. So this needs to be fixed no matter what, before I go any further, but I'll be real surprised if this fixes my problem. Unless that small crack is letting the carb suck in air instead of gas??? Has any one experienced anything like this?
     
  7. glider

    glider Veteran Member

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    The carb elbow would be gravity feed from the tank and probably wouldn't suck air but would leak gas. There is a brass replacement for the plastic one available.
    It sounds like a fuel delivery problem if you aren't getting a decent shot from the accel pump, the fuel inlet may be a problem here but the accel pump feeds from the bottom of the bowl.. I would explore that avenue before going any further.

    Johns Motorcycle Parts for Harley Davidson and Keihin CV carburetors.
     
  8. Doc 1

    Doc 1 Member

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    Change the petcock....it's the only thing left that you haven't touched or replaced. It's got to be the petcock....!
     
  9. sduquette

    sduquette Member

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    Hi Folks,
    It's been a while since I've posted here about this problem. I didn't get a chance to start working on it again until recently. Thanks for all the advise and tips. However you guys left out the most important tip of all. "If you want something to be foolproof, keep the fools away from it".
    I decided to bring the carb to a pro since I was a bit leary about pressing in the new fuel elbow. I told him about my problem and asked if he could see if my float was properly adjusted while he was at it. I couldn't imagine what else could be screwed up.
    What he found was that some "fool" (me) managed to loose the little rubber plug that goes into the bottom of the (I think, idle jet). So he put one in and she's back running like the good old days.
    By the way I looked around in my tool box when I got home that night and what do you know, there's that little plug.
    Maybe someone can benefit from my foolish mistake.

    Thanks Again,
    Steve