Tapping at high RPM

Discussion in 'Touring Models' started by Mavagrand, Aug 9, 2012.

  1. Mavagrand

    Mavagrand Senior Member

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    Washed the bike today and hoped on to air dry her. When I accelerated briskly, I heard a definite tapping..sounded like valves to me but, admittedly, I'm not that familiar with TC engines. Anyway, it would start at just about 3k rpm and go away when I released the throttle. The bike was cold when I started it so I'm thinking maybe the oil hadn't gotten into the top end because after a couple of minutes of riding the noise went away. Bike has never had this noise before, what could cause the it? If it is the oil not getting to the top end, what would suddenly cause this as the bike has never made this noise before. She's an 08 'FLHTC w/Stage 1, has 30k on the clock and I have always ran full synthetic. thanx.
     
  2. BUBBIE

    BUBBIE Well-Known Member

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    I would think that the RPM's on a cold motor...

    MY opinion;

    Even here in Az. at 80-105 I always go for a longer warm up than a few minutes... Never pushing the motor until fully warmed (for me 15/20 minutes)

    It Takes Several minutes/miles for Oil to get warmed and into the upper end of the valves/rockers/springs...
    The oil IS Not pumped in large quantities, just thru a piddle valve process out of each lifter...

    Most of what you heard was probably a COLD lifter noise.

    Think of you getting out of bed cold morning and trying to run the 100 yard dash.

    IF the noise persist, ?????

    signed....BUBBIE
     
  3. 2000classic

    2000classic Active Member

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    If the noise remains, you may have developed an exhaust leak or for the mileage on the bike, it might be a lifter becomeing weak.
     
  4. rhino 2

    rhino 2 Active Member

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    You gotta warm them up a little before you go ripping off.
    Takes a while for the oil to warm up and flow.
     
  5. Bodeen

    Bodeen Well-Known Member Staff Member Moderator Contributor

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    My first thought was exhaust leak but maybe pinging. Did you use a different fuel than normal last fill up?
     
  6. Subby

    Subby Active Member

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    I was told by the chief mechanic at my dealer that most TC engines will give you a bit of a rattle at between 2800 and 3000 rpm's when under hard acceleration. As you continue past 3000 to say 3500 rpm's the noise disappears. It does on my Ultra. That said, I would always allow my bike to warm up before hitting the throttle a bit heavy.
     
  7. R_W_B

    R_W_B Senior Member

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    All of the previous replies could be the issue. However since you just washed the bike, you might have a insulation leak on your plug wire(s). I've seen this before when they get wet. You will hear the spark jumping to ground along the water.

    If it's bad enough you can test for it in the dark, by spraying the plugs wires and surrounding area with a mist sprayer. Then crank the engine and you will see the faint spark at the point of ground (which is not always the point of the insulation crack).
     
  8. Spade5

    Spade5 Active Member

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    Dang RWB, you beat me to it.
     
  9. Mavagrand

    Mavagrand Senior Member

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    Interesting. I rode the bike yesterday, not a hint of tapping. Bike was completely dry. I'm gonna try your test, RWB, and see what happens. However, I replaced my plug wires a couple of years ago. I'll let you know. thanx.
     
  10. BUBBIE

    BUBBIE Well-Known Member

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    I believe it was Just the water, Cold from air dying, COOLS way much. That Tightened the motor and cooled it More than you thought... It is bound to be noisy when cold and revving out to high RPM... Mine will do Noise IF I did that to it.

    Like I said,:bigsmiley12: Even Here in HOT Az. I need to go at it easy.

    signed....BUBBIE