Sportster Rejet / AC issues!

Discussion in 'Sportster Models' started by mbingham666, Feb 8, 2009.

  1. mbingham666

    mbingham666 Account Removed

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    So a few months ago, I bought a used 99 xl1200C.

    It had the stock pipes, and a S/E air cleaner on it.

    Yesterday, I de-baffled my pipes, and did the "lollipop" mod to create a little backpressure. Bike was running fine afterward, so I moved on to the last of the stage 1 - rejetting.

    I pulled the A/C, and got to the stock carb. The idle mixture screw cover had been drilled off. I proceeded to remove the bottom of the carb, and noticed that someone had almost stripped one of the brass screws holding it on. By this time I was convinced that it was rejetted. So i get in there, and the jets are the O.G. 42 and 170 jets.

    I replaced with a 45 and 180, as is suggested by the article on sportster.org; put everything back together, and then got to tuning.

    This is about where everything went to (Edit).

    I started to do the above mentioned method on the .org site, started with the idle mixture at 2 full turns out from closed, and warmed the bike up. It was idling just fine, maybe a little rough.

    Next, It states to screw (speed up) the idle speed screw in 2 full turns, so I do this. Going fine still, idling fast as a (Edit), but ok.

    Now it tells me to adjust the idle mixture screw, which is a pain to get to with the AC on and that crossover pipe in the way. I get out my screwdriver, and about this time i notice that my pipes are glowing like molten steel behind the heat shields.

    I decide that a leather glove is no match for near-molten steel.

    I kill the bike to scratch my head for a while.

    I figure out what he and other people are shooting for, so i wait for the bike to cool down, close the idle mixture screw, unscrew it again...this time 2.5 turns. I then unscrew the idle speed back down to its previous position, thinking that this might still be a little fast, since the bike will now be running richer (richer = faster idle, right?).

    I get the bike somewhat idling ok, take it out for a spin, and i notice that the air cleaner is making what i can only describe as PSST PSST PSST PSST on every stroke, in some kind of maniacal washing machine gone mad tone. Like the psst from a air hose you just blip on then off again. This noise is louder than my wide open pipes. This can't be a good thing. Even my girlfriend who barely understands the difference between a gas tank and a wheel said "that doesn't sound good at all".

    I check my vacuum hose, looks good.

    I pull the A/C assembly and check where the carb mounts to the engine, looks good to me...but then again, i'm a motorcycle-retard, so don't trust me 100%

    I check the gaskets between the carb and AC, they look good.

    I get the K&N cleaning kit, and clean the filter.....replace...it looks good.

    So what i've got is one of two things, either my sportster secretly mated with a maytag, or I screwed something up.

    My first question is, what is this horrible hissing? Or is this just the sound that a jetted sportster makes?!

    2nd, Is there a better way to tune myself? I play around, and I can get rid of most of the pops on deceleration, but then the idle is rough.....or the idle is smooth and it pops on deceleration. I'm not so "hot" on the idea of sticking my hand .02 inches away from a glowing red exhaust pipe like the .org guy suggests.

    One more thing, my carb farts are less, but they are also exaggerated-ly (Edit). Much like the new sound of the A/C.

    H-E-L-P

    Sincerely,

    Someone who doesn't have the money to go to the HD dealership for a dyno-tune, and understands that drag pipes aren't the optimal way to go....I'll gladly ride a finely tuned sportster that is missing some low end torque.

    [notes]
    A Friendly Reminder - Harley Davidson Community
    [/notes]
     
    Last edited by a moderator: Feb 8, 2009
  2. Bud White

    Bud White Well-Known Member Retired Moderators

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    should have left the baffles in..

    Are you sure you didnt knock one of the breather hoses loose?

    didnt overheat it and crack the pipe at the head?

    Blow the Head Gasket ?

    other than that i got to no guesses
     
  3. mbingham666

    mbingham666 Account Removed

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    Checked the pipes, no cracks.

    The sound is definately coming from the AC / Carb area, not exhaust...not head.

    Breather hose? Other than the fuel drain line, and the bolts that vent the cylinders into the A/C, what are you referring to?
     
  4. STEVE07

    STEVE07 Well-Known Member Staff Member Super Moderators

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    Start over. screw the mixture adjustments in (don't overtighten) then turn them out 1 1/2 turns. fire the bike up,then use windex to check for any air leaks. Then try to tune the carb by ear. take it for a ride and tweak it from there. Usually if you tune a carb by ear you can get it close .
     
  5. Bud White

    Bud White Well-Known Member Retired Moderators

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    well if its bolts venting to the ac then it wouldn't have a breather hose are you sure the bolts are tight and sealed
     
  6. mbingham666

    mbingham666 Account Removed

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    Affirmative on those bolts being as tight as humanly possible.

    I've completely dis-assembled the entire thing and re-assembled twice, still have the same PSST sound. I wish i had a decent recording device as it's like nothing i've seen or heard watching youtube clips or listening to sound-clips
     
  7. Bud White

    Bud White Well-Known Member Retired Moderators

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    were they oring sealed If so you sure ya didnt tear one ?
     
  8. mbingham666

    mbingham666 Account Removed

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    No o-rings or gaskets....just spacers between the cylinders and the backplate, and hollow hex bolts with two washers on the head that screw through the A/C backplate / through the spacers and into the cylinder heads.
     
  9. STEVE07

    STEVE07 Well-Known Member Staff Member Super Moderators

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    Start it up and spray it with windex,or soap and water in the area where the sound is coming from ,if you hit the leak the idle will change noticeably
     
  10. mbingham666

    mbingham666 Account Removed

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    I'll have to try this tomorrow.

    I got my ear all around the Ham-Can, and it was emanating from everywhere...i.e. front cylinder side, rear cylinder side, top, bottom....

    My thinking was the round plate that screws with two gaskets from the backplate onto the carb itself. I reassembled exactly as it was when i first took it apart...but I thought it was weird at the time.

    It goes in this order, carb body -> gasket -> gasket -> backplate -> plastic ring with screws.

    Should it be.... carb body -> gasket -> backplate -> gasket -> plastic ring with screws.

    Sorry for my horrible terminology. I'm learning proper names as fast as I can.