chasing a noise

Discussion in 'Engine, Fuel and Exhaust' started by jwinks, Jul 13, 2009.

  1. jwinks

    jwinks Member

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    I have a '97 softtail that has a high pitched noise coming out of lower engine area that is driving me nutz. Steady throttle or during acceleration brings it on but if I roll off it ever so slightly it diminishes or backing out of it will stop it entirely. Thought it sounded like the belt was rubbing against the retaining lips on the rear sprocket but have adusted the run till I don't think it is that, slight wobble of the sprocket would account for the screech-screech-screech that speeds up with increase of speed. I had the primary chain inspection/adjusting cover off and it appears that the chain is out of adhustment, 35,000 on chain. Any thing down in there that could be rubbing intermittenly? If I take the whole cover off am I going to lunch the gasket? Any ideas? Thanks
     
  2. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    EVO engine noise that is speed/acceleration related, right? Sounds like it is coming from the engine NOT the primary? Checked the oil and it is OK? You do not have cam chain tensioners so that is good (can't be that).

    Get a candle, jack the rear of the bike up so the tire if off the ground. Have someone you trust start the bike and slowly let the clutch out so the wheel/drive belt is turning. Wax up the sides of the belt with the candle. Stop all that and take the bike out for a ride. See if it is still making noise.

    Drain the primary fluid, pop the outer primary cover off and look around in there. Make sure that the compensator nut is tight (150-165 ft-lbs. on mine - check the book, but they now have a new procedure for at least the newer bikes. See Compensator Bolt Stack Up Tech Tip - Harley Davidson Community).

    Adjust the chain tensioner shoe as per the book. If the shoe is deeply grooved, replace it.

    Using a straight edge, make sure that the drive sprocket and the clutch sprocket are lined up (if not, this can make the noise you have described). Adjust with a spacer if necessary (see the book).

    Install a new primary cover gasket and fasten the cover back. Remove the chain inspection cover and add your primary fluid volume (Formula + or Spectro Chaincase).

    Ride it. Noise gone? If not, can you get the noise to happen in neutral? If so, check with a stethoscope to try and locate the noise. If you do not have one, try a long screw driver or metal/wood rod. Hope it is not a main bearing!

    Let us know.

    TQ
     
  3. jwinks

    jwinks Member

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    Thanks TQ, that'll give me something to check. I'll get on it.

    I found that the stator plug at the bottom of the case in the front was weeping oil, not a lot, in fact I never find any on the cement floor in the shop where it sits waiting for me. It must come out after engine gets warmed up and then the wind pushes it back along the underside of the bike and some on the drive belt. I suppose when it gets on the belt between the oil and road grundge it forms a glaze and screeches on sprockets. A good wire brushing and some cleaning with solvent and it's quiet as can be, can't get a peep out of it now. Gotta keep an eye on that plug I guess, maybe a change out of stator is in my future. Thanks for the ideas.
     
    Last edited by a moderator: Jul 18, 2009