having idle problem

Discussion in 'Sportster Models' started by trat, Dec 1, 2012.

  1. trat

    trat Member

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    OK I replaced the intake gaskets on my 2000 1200XLH with a HSR carb because of a surge problem at steady throttle. I have not ridden the bike yet because when I put it back together I now have to completely close the pilot screw to get a good Idle. I am doing so other work (moving the ignition switch replacing tires and lowering the bike)) so I am not ready to put the tank back on and ride it yet. I have checked for vacuum leaks around the manifold and carb and don't seem to have any now. I did have before I replaced the intake seals. Reading the HSR tuning manual it says that if the pilot adjustment is less than 1 turn out I need a larger pilot jet. Before I changed the seals my pilot screw was at 1 1/2 turns out. I would like to get some of your ideas on this. Has anyone had this problem? It seems to me that if I was 1 1/2 turns out with vacuum leaks then with out a leak I would have to be out further. Is my thinking right? Or am I looking at it wrong? Oh one other thing I installed 10 in long baffles in my pipes which are 2 1/4 long shots. They had no baffles at all. I did this after replacing the seals. I did start the bike before I replaced the baffles and I had to close the idle jet to get it to idle. I did not warm the bike up to normal though before I installed the baffles. The baffles did not seem to affect the idle at all but it is a heck of a lot quieter now!
     
    Last edited by a moderator: Dec 2, 2012
  2. Hoople

    Hoople Account Removed

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    I am not a carb man, but I do have some HSR manuals. You have a 42 correct? Is the carb brand new or did it come off of a used bike.
     
  3. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

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    I would suspect that air is being drawn in from somewhere if the carb has been off the bike i would look at the bits where it has been disturbed
    Carb to manifold junction, vacuum pipe to the voes, or the choke fitting

    Brian
     
  4. trat

    trat Member

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    yes it is a 42 and it was on the bike when I got it
     
  5. trat

    trat Member

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    That was my first thought but I have sprayed wd 40 all around and I can't find any vacuum leaks. I even sprayed some starter fluid around the manifold and the idle didn't change. I found the leak that caused me to change the manifold seals last week this way but now nothing! If there is a leak I cant find it,,,,,I guess I should pull the carb of it again.
     
  6. trat

    trat Member

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    I would suspect that air is being drawn in from somewhere if the carb has been off the bike i would look at the bits where it has been disturbed
    Carb to manifold junction, vacuum pipe to the voes, or the choke fitting


    I can find no vacuum leaks, I even used butane around the manifold and the carb mount......NOTHING. Still won't Idle with the pilot screw over 1/2 turn out from closed. As soon as I crack the pilot screw it starts to die.......I am out of ideas!
     
  7. fin_676

    fin_676 Experienced Member Staff Member Moderator Contributor

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    Have you checked the condition of the vacuum pipe between the top of the carb and the voes on some models there is a t in the vacuum pipe to also operate the petcock if the vacuum take off on the carb was drawing air that would make your mixture weak

    Brian
     
  8. trat

    trat Member

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    My bike has a custom tank and no vacuum petcock, sorry, I should have mentioned that. I can't find any vacuum leaks using WD40, Starting fluid, or bleeding butane from a torch through a hose and checking all the joints and hoses. It is hard to get everywhere back behind the carb though even with the tank off and using a remote tank. I guess I'll pull the carb back off this weekend and check every thing visually, See if I screwed up anything!