Backfire or Decel Popping

Discussion in 'Engine, Fuel and Exhaust' started by Jack Klarich, Oct 1, 2016.

  1. Jack Klarich

    Jack Klarich Expert Member

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    GOT BACKFIRING?

    Backfiring in the exhaust system of your motorcycle is created by the same three necessary elements for combustion inside the engine; oxygen, fuel and ignition. Because the heat of the exhaust will supply the ignition, let's discuss the other two. The backfiring during acceleration is a serious engine related (cam timing, bad valve seat seal, etc.) problem and can not be fixed with air/fuel mixture changes.
     
    coopernicus likes this.
  2. jamesearl

    jamesearl Senior Member Contributor

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    only occasionally on deceleration,on an FLHX.Not so far on the FXDWG.Though it has hiccuped after first starting.
     
  3. Jack Klarich

    Jack Klarich Expert Member

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    Nota today with baffles knocked out
     
  4. CRCKR

    CRCKR Active Member Contributor

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    I was messing around with idle@temp settings in my FP3 this morning (knowing that I can go back to a good flash after manually messing up the map) and got backfire when the engine was cold and accelerating. I had set the bike to idle too slow at too low a temp. 1100 @ 75 degrees (f). I wish I knew more about manually adjusting the tuning but I'm gonna stick to the AutoMap or V&H PreBuilt maps unless / until I do.
     
  5. Jack Klarich

    Jack Klarich Expert Member

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    If you can set timing each cylinder u r way ahead of the game
     
  6. Jack Klarich

    Jack Klarich Expert Member

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    However JMO f you have too lean you will still have some decel popping due to un burn gas and or a leak in system, my M8 with baffles knocked out does not pop, maybe cuz each cylinder has its own knock sensor like your car does a big change for the better IMO
     
  7. dbmg

    dbmg Experienced Member

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    I have been noticing as of late my 08 EG on decal has been popping more and more over time. Its all stock and runs strong, so I attribute it to the mufflers packing burning out.
     
  8. gator508

    gator508 Senior Member

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    Have you checked the exhaust for leaks? My 08 gets loose from time to time, re-torque of the flange nuts helps out.