EVO Vibration

Discussion in 'Engine, Fuel and Exhaust' started by brt650, Jun 22, 2010.

  1. brt650

    brt650 Member

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    Hello,
    I've read most posts on EVO vibration. But after checking the common concerns I can't find anything that stands out.
    The concern I have is my footboards vibrate so much at 100 to 120 km/h that my feet go to sleep and come off the floorboards. It's a 1996 FLSTC 80,000 km's. I have replaced the floorboard rubbers. I have installed a DYNOJet kit to the carb. Just fitted a Andrews EV27 cam. Replaced the rear tyre. The only thing that has changed ,is the new tyre having a larger diameter has moved the vibration up from 90-100 to 100-110 km/h. I've tried with and without the screen as well. I don't get the vibration through the seat or bars. Just the floorboards. 130km's is unbearable.
    I know I need to harden up ,but there must be a logical answer.They can't all be like it. I've owned the bike since September last year.I've only done 2500km's in that time.It's not an enjoyable ride at all. Up to 90km/h it's fine. Except if it's revved out.That's when the mirrors moove in all sorts of direction's. True I'm a jap rider in the past. But if anyone can help me pinpoint the area I should be looking at ,it would be greatly appreciated. Sorry to be another whinger,but how much do they vibrate?
    I don't have a bike I can compare it too. Not too many Harley owners are going to let me ride there bike to test it.
    Thanks in advance
    Brian
     
  2. glider

    glider Veteran Member

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    Brian

    Your bike is in the era of the NON balanced softails. I have ridden a few and they do vibrate like you say where your feet will vibrate off the boards. There's no answer to lessen the problem you are having short of a newer bike with the balancers in the engine case (the "B" model engine).
    They eliminate the vibrations to almost nothing. This required a redesign of the entire engine case to facilitate this design so it was a problem for Harley or they wouldn't have spent the money to redesign it to the newer style.
     
  3. BOBFLHTC

    BOBFLHTC Active Member

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  4. TQuentin1

    TQuentin1 Well-Known Member Staff Member Moderator

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    Welcome to the Forum. There is a lot of great info in the self-help pages and in the heads of your fellow members.

    I just read Glider's comments above, and so am editing my response here. My experience is with a Dyna that is a rubber mounted engine. So it is not apples-to-apples comparison. Do have to defer to Glider's experience on this.

    I have a '91 EVO, and the symptoms you are describing are not normal. The concern I have is that vibration may be indicative of too much runout on your drive shaft/pinion gear. I am afraid the only way to check that is to gut the cam chest and then measure the runout on the shaft.

    Before doing that, you did have the new tire dynamically balanced, right? I would also get the shop to check both the front and rear tires to make sure they are not out-of-round. This is a long shot, but much simpler and easier than getting into the cam chest.

    TQ
     
    Last edited: Jun 22, 2010
  5. HDDon

    HDDon Experienced Member Contributor Retired Moderators

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    I agree with Glider to a point. I own a '94 FLSTC with mod. carb. SE pushrods and an EV27 cam with dyna 2000 ign. While the newer softails have a counterbalance and are much smoother the older evos can be made to ride much smoother than you are describing. Have you checked the motormounts? Is your primary chain adj. correctly? When you reach the speed that the vibration occurs have you pulled in the clutch to see if some of the vibs are coming from unbalanced wheels. Is your drive belt to tight or to loose? A loose top motor mount or loose primary chain can make the evos. shake pretty bad. If everything is tight and adjusted correctly you may need to look into one of the newer softail with a "B" motor.
     
  6. dhorne

    dhorne Active Member

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    Good advice HD DON , I have a 96 fxstc with no problems unless i am in a gear too long when I am rolling hard
     
  7. Bud White

    Bud White Well-Known Member Retired Moderators

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    my fatboy a 98 shakes like crazy when your pulling the power its impossible to hit 4th gear under full throttle while um drag racing my buddy as the floor boards shake so bad i cant hit the shift lever

    Also Different cams will move the vibration around and cause it to vibrate more at certain rpms than it did b4
     
    Last edited: Jun 22, 2010
  8. HDDon

    HDDon Experienced Member Contributor Retired Moderators

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    Bud I feel like I'm in the minority here. I must have one of the few softails that doesn't shake the fillings out of teeth. It is just one mans opinion but I do believe that set up correctly an EVO hardmounded engine can be smooth enough to ride hard. My FLSTC had over 135,000mi before I sent the motor back to the MOCO for reman. Since it was returned and the mods replaced I have put another 20,000mi and it remains a very rideable bike. My boots stay on the floorboards at all speeds. Vibration and the feeling of it is a subjective thing. Maybe I just tolerate it better.
     
  9. Bud White

    Bud White Well-Known Member Retired Moderators

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    your right it can be the set up .. keep throttle below about 3/4ths on mine dont run higher rpms and keep it below 73mph and its smooth and rideable all day long drop it down to 65 and its even smoothers yet and wind doesnt interfer
     
  10. brt650

    brt650 Member

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    Thankyou all for your interest and input.
    A new bike would be nice for sure.My wife agrees with this comment ,Thanks Glider. Not going to happen.I've grown to like this shed ornament. It has some history and with this I'd like to keep it.
    The wheels have been balanced.
    I have researched the Balance Masters items and haven't read enough positive remarks to get them.
    A 6 speed O/Drive box would cure my cruising symtoms.
    It's like the crank is out of being true. A H/D tech suggested if the stator had been changed and the compensator nut removed with a rattle gun it may have knocked the crank out of being true. Hard to believe, but if it has that could explain it.
    Anyway I'll keep looking and keep you up to date with anything that works.If it's man made ,it can be fine tuned. Ha ha. Money wise, it would cost me $20,000 to update to a new bike. I think I'll get some gel shoes.
    Thanks again
    Brian :guitar