Rush slip on pop on decel

Discussion in 'Dyna Models' started by choochooharley, Apr 19, 2011.

  1. choochooharley

    choochooharley Member

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    On my 09 street bob. I recently put on rush slip ons with 2.25 baffels k & n air filter with stock air cleaner box and a doebeck tfi. I have tried every adjustment possible on the tfi and even went back to stock air filter and still can not get the pop on decel to disappear. Does anyone have any Ideas?

    Thanks
     
  2. BUBBIE

    BUBBIE Well-Known Member

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    I don't Know all about the pipes,,,, Seems though, I have heard those pipes do have that characteristic of the POP on decl...

    Your Harley should have the "gas shuts off on decl. feature" on this new of a bike..

    I know my 09 FLHR throttle by wire does shut off the gas so it won't pop..
    Harleys STOCK are sooooo lean to start with this Feature is Needed..


    I doubt your problem is a lean condition caused by the TFI ,,,,, IF HOOKED UP correctly and working (set to the Suggested settings)... If set Close to their settings it should function great...

    The only two Pots that Most will set a little differently are the First Pot #1 (green),,
    that is Set at Fast idle(2000 rpm) after warmed... Close pot one and then Open it,,,, Turning Until TOO MUCH fuel is noted by the motor stumbling then turn back IN (down) until smooooooth and then Just a WEE bit more,,, (Wee= very Little)..

    On the # 2 pot IF gas mileage is Bad, this pot can be turned in a 1/2 number or so from Suggested setting ....

    Just more information please??

    ??? do you back-off at High RPM when pop occurs or is it at Normal Off speed decl. and Just How Big a pop and many is it...

    IF it didn't do it Before the exhaust change, it is probably the exhaust muffler system.. Maybe some one out there with the Same mufflers will chime in here..

    You are going to get "intake leak" and maybe other things to check from others but I doubt it to be the problem...... Exhaust Characteristic is my thinking.

    On some muffler systems the pop is going to be there and It is hard to tune it out...

    signed....BUBBIE
     
  3. bwalsh22

    bwalsh22 Junior Member

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    Agree with the pop just being there in certain conditions. My Bob, with Big Sucker Air intake and Thunderheader 2-1 has popping on decel under certain conditions. It is not all the time, but usually at the lower speeds and the speed of deceleration. If fast decel, no issue, but if a slow decel based on riding out the gear it pops, say in 2nd or 3rd between stop signs.
     
  4. choochooharley

    choochooharley Member

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    It happens at I guess what would be a fast decel if you let off the throttle at speed or down shift its kinda a backfire i guess if it was the gurggle i could live with that but its a back fire and it varies in how many but usually 2 or 3....
     
  5. glider

    glider Veteran Member

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    The size of the baffle is contributing to the popping on decel. Considering your pipes are 1 3/4" you can see that back pressure is almost non existent.
     
  6. choochooharley

    choochooharley Member

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    I had a sneaky suspision that was part if not all of the problem....I am guessing ill have to buy the 1.75 baffels....or does anyone know of a way I can modify this 2.25 baffel....
     
  7. glider

    glider Veteran Member

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    You would no doubt see an improvement in running with the 1 3/4" baffles.
     
  8. BUBBIE

    BUBBIE Well-Known Member

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    I think that is the HD shutting OFF the fuel to the injectors and NO pop at High speed decl... After you go slower it turns OFF or I should say TURNS ON the fuel... so pop is there... Not on my FLHR but that is a whole different game.. and Parts..


    Sure LOVE MY TFI....

    signed....BUBBIE
     
  9. choochooharley

    choochooharley Member

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    Mine does it more on the fast decel if im at low speeds it doesnt do it but if i let off the throttle at say 45 or higher it pops away unless i leave the throttle open a little.....
     
  10. BUBBIE

    BUBBIE Well-Known Member

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    I doubt you can TUNE it out.. It is simply NOT Enough back-pressure and the 1.75 baffles should be tried... Like Glider stated..

    signed....BUBBIE