new noise...

Discussion in 'Touring Models' started by Mavagrand, Sep 26, 2013.

  1. Mavagrand

    Mavagrand Senior Member

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    ..on my 08 FLHTC. Sounds like a "shushing" with background light, very light tapping, like something is vibrating. I've just installed new exhaust (2in1), all clamps and shields are tight. (would an exhaust leak make this sound?)...i didn't use a torque wrench on the head pipes. It is RPM related, I pull in the clutch it is still there when I rev it..I've checked the brake pads and the cam chain tensioner. Would the compensator nut make this sound? Sometimes it sounds electric, like it's a sparkplug wire or something. it is driving me nuts. My bike is stage 1,(high flow AC, TFI, and Rinehart 2in1). Any ideas, I've got a trip to NC planned in November and would love to have this sorted out.

    thanx, Mark
     
  2. Jack Klarich

    Jack Klarich Expert Member

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    Re check the exhaust first, torque the header nuts to 10 ft lbs
     
  3. Mavagrand

    Mavagrand Senior Member

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    Jack, I'm actually thinking about taking it to the HD shop saturday and let them do it. I know they'll probably charge me an hous labor but I cannot get my socket to seat on one of the front cylinder nuts. I used a box wrench and tightened as much as I could. for what its worth the sound was there before I changed exhaust. It's been there for a couple of months..I was actually riding the bike when it started. those who listen to the motor don't hear it but I can.
     
  4. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    Mark,

    The best place to start looking for a "new" noise is the last thing you did to the bike (or things) before the noise started. So thank you for identifying that you have just added the new exhaust system to the engine.

    So this is the most likely source of the "new" sound. Torquing the nuts on the head studs is a good idea as a starting point, but then I like to "snug" them up a bit more once the engine is good and hot. That assumes that you do not have a leak caused by one of the crush washers getting damaged on assembly. So lets try this to look for leaks:

    • Recruit a buddy or spouse (flowers?) to help you
    • Get some heavy work gloves or folded towels (2)
    • Park the bike somewhere quiet
    • Start the bike and listen for the sound
    • If it is there, cover the end of each muffler one at a time, and then both (briefly) and listen for escaping exhaust
    • Helps to have your assistant do the bullet above while you lean in and listen for the leak
    • Repeat above two bullets, positioning your ears close to each mated joint

    If you can NOT find a leak in the exhaust this way, then it may be something else. But let us know how you make out looking for an exhaust leak before we start looking further.

    Harley Davidson Forums

    Cheers,

    TQ
     
  5. Mavagrand

    Mavagrand Senior Member

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    thanx T, I'll do that. As I mentioned to Jack, this issue started before I installed the new exhaust, although I'm not eliminating the possibility, I'll check for leaks when I get home. question on exhaust leaks, could I put some baby powder around the clamps on the headpipes and look for "puffs" when I start the bike? Seems I could check that way
     
  6. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    Not sure what would happen to the baby powder when the pipes get hot. Would hate to have it "burn" onto the pipes and then create more work getting that off.

    If you have a leak at one of the clamps, the method I described will quickly identify that. In fact, if the exhaust is escaping at a clamp, you can usually feel that with your hand by carefully holding it cupped near the clamped joint and following around the pipe with your hand. If it is at the head, it is a bit harder to "feel" (don't burn yourself - the heads and header pipe at the heads are VERY hot!!).

    Since you think the sound may have started BEFORE you replaced the exhaust, as plan "B", I would jack each tire off the ground and give the tire a spin to see if you hear the same sort of "shushing". This may find a warped brake disc. Of course if the sound is there when the engine is running but the bike is not moving, this is a moot point.

    Cheers,

    TQ
     
    Last edited: Sep 26, 2013
  7. Mavagrand

    Mavagrand Senior Member

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    I got to thinking, I've had this same noise before so I reviewed my posts. Way back when I installed a SE Compensator to illimunate that annoying starter knock that was associated with the stock compensator. On one post I commented that the annoying "shhing" sound was gone. I wonder if the nut has loosened on the complensator? My plans for the weekend are to check for exhaust leaks, fix any that are found and, if the noise is still there, remove the outer primary and check the compensator nut.
     
  8. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    If there is even a CHANCE that the compensator nut is loose, DO NOT run the engine until you check that. I would do that first. I have had the compensator nut back off enough to let the rotor wallow around on the shaft. It eventually caught a magnet on the stator and the drive shaft sheared out all the dogs on the hole in the rotor. Then the rotor tore up the stator!! So my little job of some fluid and a gasket to check/retighten the compensator nut turned into an expensive one of replacing the rotor, stator and (you guessed it!!) voltage regulator that fried when the stator shorted out!!

    TQ
     
  9. Jack Klarich

    Jack Klarich Expert Member

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    Number 2 on what T Q posted
     
  10. Mavagrand

    Mavagrand Senior Member

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    Still haven't pulled the primary cover yet, but will start tomorrow. One more question, as I was checking things over this weekend looking for the culprit (Jack, I tightened the exhaust to 10 ft lbs) I pulled the plugs just to check them. They've been in for a few years now. The front plug was pretty crusted up. Black sooty (EDIT) on it. The rear plug was nice and brown. I cleaned this plug and put it back in. Could the plug be creating this noise somehow?


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    Last edited by a moderator: Sep 30, 2013