Harley vibration at above 65mph

Discussion in 'Mechanical & Technical' started by SparkyzGixxer, Apr 20, 2010.


  1. Ok my buddy has a 98 Harley softtail with the 80 cu. In. Motor. He says that he can't really go over 65 without uncomfortable vibration. He was told it is normal for that motor and all. I think that there is something not right.

    What are the possibilities? My friend lives in anchorage alaska so I will get as much info as I can. But only being able to do 65 just don't sound right. Even for a Harley.
     
  2. Wyckedan

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    A Harley can get up to 65mph???
     
  3. ducatichick

    ducatichick Wench

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    Engine vibration, and/or other kind(s) of vibration?

    I'm brainstorming here: improperly balanced wheel(s), scalloped front tire, loose steering bearing, loose/damaged motor mount (does this thing have hard motor mounts or rubber bushings?).

    Has it always been like this, or did it get worse over time or...?
     
  4. what she says
     
  5. My first guess would be to inspect/tighten/replace motor mounts.
     
  6. james1300

    james1300 Track School Dazed

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    When was the last time the bike was looked over and everything tighted up?
     
  7. It would be helpful to know the model of softail.... ie does he have the 21 inch front tire or the 16.... my bet is that it is a FX with a 21, and as a 98, betting before the twin cam switch over. The motor on the Softail is bolted directly to the frame with no dampening, your vibration isolation is from counterbalancing the motor... which really didnt come into having any significant affect before the twin cam set up.
    He has a couple of options... make sure everything is all torqued down.... put a bigger fatter 16 inch tire up front... trade in for a new softail.... trade in for a newer FL tour bike. OR.... ride it, and pull over at every Starbuks out there....:mfclap:
     
  8. If it were me I would start with the wheels follow him and watch for a possible bent rim. then get up beside him and look for any odd moving parts. then work to the shocks and up from there. Dads Ultrarglide classic at 65 does not vibrate abnormally.
     
  9. I will +1 that. When I got my bike it was hard to even ride at all, but even after
    Replacing:
    tires (it came with the OEM tires- 34 years old and 27K miles they were smooth and hard as... well you get the picture)
    shocks
    swing arm bushings
    fork oil

    while it was WAY better it still had this wierd feeling over 75. I found out that someone had replaced the main motor mount with allthread that was 1/2 the diameter of the stock bolt :rant

    that fixed it.

    check the engine mounts- if they are rubber see if they are hard or split.
     
  10. MadManx

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    Its a Harley.
     
  11. they didnt rubber mount those engines until 2003 right? I rode a harley that wasnt rubber mounted, i could certainly go over 65mph.
     
  12. :roll:

    Not to be like that, but srsly, if your friend can't figure out what is wrong him/herself, bring it to a shop. Don't rely on a bunch of people to tell you when they have no idea, either. Can't diagnose a problem like that. It's like 10 people with blindfolds on running their hands over an elephant and trying to decide what it is. Ridiculous waste of time.

    As a shop owner, it could be alot of things, as Ducatichick said also. BTW it should not be anything specially shakey over 65 if it isn't under 65...rubber mounted engine not a factor here.

    Bring it to a shop, and yeah, like Dragracer said, make sure they tighten EVERYTHING up, too.
     
  13. the softail didn't get the Twin Cam B (balanced) motor until 2000.
    Harley never made a rubber mounted softail. (still don't)
    The closest thing would be a Wide Glide assuming you mean the Softail model with the 21" front wheel and not a Fat Boy or Heritage all with the softail chassis, but with the bigger front end and 16" wheel.
    Some of the after market frames had softail styling with the Wide Glide style rubber mounts.
    Gotta watch those as well on bigger motors...

    The older softails feel like a paint shaker is underneath you when your rolling. Its different for sure. Not sure if I actually miss it, but you knew you were on a Harley fo sho!!!

    The vibes can damage motor mounts if not maintained properly.

    Tell him look for broke stuff, if nothing is busted he should try to ride another similar vintage softail.

    It might just be the good vibrations of the solid mounted motor!
     
    #13 NoQuarter#121, Apr 20, 2010
    Last edited: Apr 20, 2010
  14. OK, so this proves my point. Even the guy doesn't know what kind of bike he is asking about for his friend.
    Also, even if he was able to find "broke stuff", it needs to go to a good mechanic, anyway.
    and, if he doesn't know what it's supposed to feel like already....
    anyway.

    BTW single fire ignition upgrade helps alot. Also selling it and getting a StreetRod, which is nice and smooth.
     
  15. dragracer1951

    dragracer1951 Moderator
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    I think the first thing I'd check after the motor mounts is the engine / tranny alignment. They want to pull the tranny sideways...
    Just a thought.
    My Shovel has had it's tranny get a little out and it'll shake. Same with my Norton.
     
  16. id say front motor mount or wheel-- take it in or check it out before something happens on the road
     
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