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Backfiring

Discussion in 'Motorcycle Tech Talk' started by scraggs, Nov 10, 2007.

  1. scraggs

    scraggs New Member

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    hi i just bought an 08 softail before i picked it up i had the dealer put a set of vance and hines pipes on it, when i back off it seems to backfire and crackle really bad the mechanic told me all new harley's do this because of the fuel injection and it will be louder because of the pipes i had put on, does this sound right or is he not quiet telling me the truth. thanx for your help..... scraggs from down under.
  2. voodoochild

    voodoochild New Member

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    sounds like bullsh*t to me but I'm sure somebody else will chime in with a better answer than mine. Alot of guys here have changed pipes on the new bikes, and I'm sure they will have an answer.
  3. fxrsrules

    fxrsrules New Member

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    ya got to love some of the stories those steelerships come up with. sounds like a bunch of crap to me to. You may be running very lean because of the changes they did. I wouldn't ride it until the problem is fixed.
  4. cowboy

    cowboy Moderator Staff Member

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    Did they do A Remap to to with the pipe's change , This will cause a back fire when letting off the throttle , also double check the bolts that hole the pipes into the head's sometimes they will work loose fome new install , this will let the engine suk in clod air & backfire
  5. VYBR8ER

    VYBR8ER New Member

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    You are not being told a BS story by the dealer. The 07 and 08 bikes are programmed very lean by the factory to meet the EPA requirements. Putting on a set of less restrictive pipes will cause popping. If you didn't have them do a Stage I download, it might help get rid of the problem. You have what is called lean misfire. When you cut the throttle the fuel is shut down but the engine is still turning and drawing air, causing it to go lean enough to not fire. What little fuel there is going into the engine is then dumped into the hot exhaust and it will ignite and pop. I ALWAYS recommend a Power Commander when changing to anything other than the restrictive pipes that Harley sells to meet EPA. Can't blame this on Harley, they have to stay within the federal guidelines or pay some pretty hefty fines for every bike they sell that doesn't meet the standard. The new Power Commander is EPA approved, but cannot be loaded with anything other than approved maps so the old dyno tuning doesn't work to get past the EPA approved engine/pipe combinations.
  6. chucktx

    chucktx Moderator Staff Member

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    thanks vybrater......really appreciate your "inside track" of insight!!!!
  7. voodoochild

    voodoochild New Member

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    Good to have him around, ain't it Chuck! :D
  8. chucktx

    chucktx Moderator Staff Member

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    yup. he is a plethera of quality info...........:)
  9. hotroadking

    hotroadking Super Moderator Staff Member

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    Your other option vs the powercommander and the epa maps is to get HD's SERT or Screaming Eagle Race Tuner, about the same costs.

    They have maps that you can download that will help you get rid of the lean pop problem, also you should replace the air filter and backing plate with one from Arlen Ness - the Big Sucker, it has a K&N type washable air filter, the HD SE filter has to be replaced when it comes time (Leave it to HD to find another revenue stream)

    The SERT program can be loaded onto a laptop then connected through a cable (Get the HD cable) to your bike.

    You simply find a map that is close to your changes, and upload the map, go for a ride and see if it helps, bike should run better, cooler and reduce the pop.

    I would also check the connections on the mufflers and headers, if they did loosen the header bolts they tend to come loose after being reattached, so retighten them, and check the clamps on the mufflers.

    Get the SERT from Jenny at Charlies HD in Charleston HD, or Zannotti HD, PA or ChicagoHD in of course, Chicago.

    Google zannoti or Chicago HD for the web sites, 20% off everyday, no tax, Jenny does a good job at Charlies HD also 25% off on aftermarket parts, it pays to shop.
  10. skull2007

    skull2007 Active Member

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    so . . . the new pc can't be fine tuned anymore. is that whats up. you have use a epa approved map:witsend:
  11. skull2007

    skull2007 Active Member

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    just spoke to PC. what they have are two types of PC; the EX and the race version. the ex is limited as to what you can adjust:banghead: . they seemed to really focus on limiting the timing. but the rep tells me that the race version is just like the olde ones, can adjust all you want:rocket_bike:
  12. hotroadking

    hotroadking Super Moderator Staff Member

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  13. skull2007

    skull2007 Active Member

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    i see lean days in our future. :angry:
  14. hotroadking

    hotroadking Super Moderator Staff Member

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    Not me I'm CARB resistant, I have a carb :roflmao:
  15. skull2007

    skull2007 Active Member

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    there's always the zit faced computer geek....... I hope:eek:
  16. Hrd Rider

    Hrd Rider New Member

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    Decel Pop/Backfire

    Just bought a 2008 Heritage, had Rinehart Slip On's and K&N Hi Flow AC and SERT put on prior to delivery. They ran a Dyno Set Up at 3 K until I clocked up at least 1000 Miles, they used a base map for set up. Bike ran good but did have some decel pop. At 1100 miles I had a supposed SERT GURU at another Stealership perform a Dyno Run and Setup, the TQ =82.9 and the HP=73, Air/Fuel Ratio 13.5 to 14 flat out to 5.5k. However, even after my taking at least 5 test runs then each time having the tech make computer adjusts to SERT it still has annoying decel pop. He finally said it must be the fault of the Rineharts and he didn'tknow what else to do. He also wanted to change the timing and I refused. I checked all exhaust clamps and header pipe bolt tightness for leaks, found none.:banghead: When spring comes I will have to find a tech somewhere who can solve the problem. I've had same problem with the last three Harleys, not being a tech I blame it all on EFI. I do know that the decel pop can be eliminated.
  17. skull2007

    skull2007 Active Member

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    sounds like your pops are from being alittle lean. it's a common problem :witsend: have you thought about teaking it a little yourself:eek: another thing to watch is the clamps. you may want to compare the clamps. see if the stock ones are better. i have V/H and the clamps suck. i went back to using the stock hd ones. bottom line is you should be able to get rid of the popping and farting, at least most of it, especially with using slip ons
  18. Hrd Rider

    Hrd Rider New Member

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    Backfire

    The tech said he had enriched fuel at Zero Throttle Position??? I don't have a Lap Top so I can't do any tweakin on the SERT, I would be afraid to try it anyway as I would probably ruin my A/F Ratio and maybe make things worse. I'm not sure if the clamps are stock or not, I do know there is no sign of an exhaust leak,(discoloration) where Slip On's are clamped to header pipes.
  19. chucktx

    chucktx Moderator Staff Member

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    a way to check for leaks at clamps......get a spray bottle of soapy water....start the bike....cover the exhaust using some gloves and a rag...dont stop it up, just cover it......spray the soapy water at the joints....:)

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