Idle Drop

By Mark DiPietro & filed under Harley Tips.

Question for Fix My Hog Premium member. 2007 Harley Davidson Ultra Classic. When I first start out on the bike, she will backfire when down shifting and cut off when coming to a stop with the idle dropping from 10,000 to 0. After riding for about 10 miles, this problem usually subsides and she idles fine around 10,000 rpms. Any suggestions?

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Fix My Hog Answers Back firing when down shifting is probably decel popping. This is caused by a lean condition. If you have a Power Commander or Vance & Hines FP3, you can add fuel @ 0% throttle. The FP3 also has an auto tune feature and another section designated to decel popping. As for the m/c stalling – Check for trouble codes and check for an intake leak.

Related Fix My Hog Videos:
http://www.fixmyhog.com/video/custom-efi-mapping-installation-001395/
http://www.fixmyhog.com/video/vance-and-hines-product-review-007293/
http://www.fixmyhog.com/video/vance-and-hines-fuelpak-3-install-007295/
http://www.fixmyhog.com/video/troubleshoot-with-harley-error-codes-008010/
http://www.fixmyhog.com/video/twin-cam-harley-intake-seals-replacement-008713/

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Discussion
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13 Responses to “Idle Drop”
  1. Tyrone Sanchez
    Tyrone Sanchez

    My Dyna was backfiring yesterday, then I heard a loud pop and the oil dipstick popped out…what caused that to happen

    Reply
  3. jhre123
    jhre123

    Hmmm… 10,000 rpm idle huh? Well seems to me like you’re revving it a tad too high LOL….

    Reply
  5. Al Donaldson
    Al Donaldson

    There are other problems that may cause this and do not leave a trouble code! I have a 2007 softail custom that would stall when I stopped and sometimes the idle would move to 1400 – 2400 rpm’s. When I turned off the ignition then restarted, the problems cleared, no trouble codes. This has gone on since I owned the bike from new. No help from HD since they could not repeat the problems and no fault codes! Recently, I met a rider who had similar issues and asked if I had experienced them. He told me he found out HD had a bad batch of TPS modules, (Throttle Position Sensor), and had his replaced and has replaced and the problem has never returned. I had mine replaced and also replaced the cylinder head temperature sensor and the issue has not returned.

    Reply
  7. Ronald
    Ronald

    When I crank my 04 Road King, the engine jumps to around 2,000, sometimes 2,200 rpms. After 2-3, 3-4 or so, minutes, it starts eventually backing down slowly to where it should be: 1,000 rpms. I cant figure out what is the issue. Diagnostic shows no codes. Ive cleaned IAC sensor. . .. no change. Not sure how to check TPS, except simply to replace . Any advice? Thanks

    Reply
  8. eugene
    eugene

    I have an’06 Road King EFI, while riding over the weekend with friends, we stopped at a traffic light, and the idle dropped so low the bike stalled. I got it to start back up, and kept feathering the throttle. this continued until we stopped at our destination. when we finally headed back home, the bike started up no problem, and it wanted to stall only once. the bike ran fine, no hesitation of any sort. where do I look to start diagnosing ? thanks

    Reply