new motor pinging

Discussion in 'Engine, Fuel and Exhaust' started by fattyboy, May 5, 2012.

  1. fattyboy

    fattyboy Active Member

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    Hi all,ihave a03 fatboy.just rebuilt motor.it has a stroker flywheel 4 3/8,se pro bigger bore cyls in which have been bored 10 over,tw9f cams,se pistons 10.5-1,se cnc htcc heads,stock 42 mm mulini carb.twinn tec ig. mod.tc88 settings are at mode 1-int.timing set at 1-advance slope set at 3,I have set at different settings still wants to ping when i stand on it alittle,motor only has 140 miles on it.The pistons have a little dome on them not much. just cant get the ping out of it dont want to waste the motor! Any body have any ideas.Please help. Thanks. Bill.
     
  2. Hoople

    Hoople Account Removed

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    Heat up the motor and measure the compression w/ a gauge, both front and rear. At what RPM does it ping at.
     
  3. R_W_B

    R_W_B Senior Member

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    What kind of gas are you using. With 10.5:1 pistons you are gonna need the highest octane you can buy.
     
  4. Jack Klarich

    Jack Klarich Expert Member

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    If your Twin Tech has an adjustment for timming take a bit of advance out and ride it, do this in small increments, Keeping in mind most bikes over 10 to 1 will ping with this junk gas
     
  5. HDDon

    HDDon Experienced Member Contributor Retired Moderators

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    Like the others I suspect this is directly related to the gas. have you tried an octane booster?
     
  6. Jeff Klarich

    Jeff Klarich Well-Known Member Contributor

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    I have 10.5.1 as well and I run the highest octane I can find, I also add a little octane boost now and again to help out. Haven't had any problem as of yet.:D
     
  7. BUBBIE

    BUBBIE Well-Known Member

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    GOOD Gas, 92+ and Retard the timing.

    Hot days are the worst.

    signed....BUBBIE
     
  8. fattyboy

    fattyboy Active Member

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    It wont ping until it hits 200 dg.its just like clock work.

    Chaveron 92 oct.

    its back to 0

    Yes oct.boost 104

    Done that the timing is at 0 with 104 octane boost and still pings.
     
    Last edited by a moderator: May 18, 2012