Backfire or Decel Popping

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

  1. Jack Klarich

    Jack Klarich Guest


    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

    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 Guest

    Nota today with baffles knocked out
  4. CRCKR

    CRCKR Active Member

    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 Guest

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

    Jack Klarich Guest

    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 Guest

    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 Well-Known Member

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