Carb problems I think

Discussion in 'Engine, Fuel and Exhaust' started by 173ABN, Jan 31, 2009.

  1. 173ABN

    173ABN Active Member

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    Just purchased a 93 softail at a great price (I hope) it runs pretty good but I needed to keep the choke out. plugs look to be running very lean. Tore into carb and replaced slow and primary jets 40 and 175, runs better but now keeps backfiring on startup only wants to run with choke half way in. While riding if you throttle up very fast backfires and misses. Any ideas or help would be deeply appreciated.
     
  2. glider

    glider Veteran Member

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  3. 173ABN

    173ABN Active Member

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    Thanks I'll give the jets a try
     
  4. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    After making the changes that Glider suggests above, if you are still having some problems with popping, backfiring, or even having to run with the enricher pulled out some, check for leaks on the intake side. The "choke" is actually an "enricher" so you are having to add extra fuel to the bike to get it to run. That would suggest that you may have an air leak on the intake side. See some of the suggestions here:

    Fuel and Carb Related Issues - Harley Davidson Community

    TQ
     
  5. 173ABN

    173ABN Active Member

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    Thanks I'll check for leaks first since I can't get the jets foracouple of days
     
  6. 173ABN

    173ABN Active Member

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    The pipes and air cleaner are stock I have checked for intake leaks and I don't seem to have any.
     
  7. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

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    i had a similar problem with my 92 softail although i had the correct jets in the carb i did go up in size
    think i had 45 slow jet and 180 main but running was very erratic a lot of backfiring on acceleration
    if i let it run to warm it up after a few minuts it would cut out and be very difficult to start
    as the weather got a little warmer would run a bit better but would cut out if i closed throttle and slowed down (had to slow down for 30 mph speed limit)
    had to wait about a minut then would start and run ok for the rest of the day
    did a lot of head scratching and some research found that the most likley cause was carb icing
    this was with stock air cleaner and exhaust neither the 93 sportster or the 94 dyna suffer from this problem only the softail

    but it does depend on teperature a little and amount of moisture in the air

    Brian
     
  8. 173ABN

    173ABN Active Member

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    Thanks, But I dont think I am icing up I am in South Florida
     
  9. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    If you have changed out the jets and checked for intake leaks (found none) but are still having problems, I think you should drain the tank and pull out the valve and filter from inside the tank to make sure it is not clogged with crap. While you are draining it, see how the gas is flowing from the drain hose you are using. If it is not a good strong continuous flow, it suggests that something is blocking the gas exit from the tank. Probably should replace the fuel line from the tank valve to the carb anyway.

    If you have not changed the jets yet, when you do, spray out the orifices with a can of carb cleaner with the little red extension on the can valve.

    TQ
     
  10. 173ABN

    173ABN Active Member

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    WOW!! I did as you all advised cleaning the entire carb, replaced the jets with a 45 slow and a 185 main (thats all the local HD dealer had), drained the tank cleaned the valve and replaced the fuel line and guess what she runs like a champ!!
    YOU GUYS REALLY KNOW YOUR STUFF
    Thanks alot