Engine missing at both high and low speeds. - Harley Davidson Forums: Harley Davidson Motorcycle Forum
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Old 09-01-2019, 01:00 PM Thread Starter
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Engine missing at both high and low speeds.

I have a 2009 XL1200L with about 12,000 miles on it. Started running rough and missing badly at low speeds and runs better at high speeds but still has a slight miss. I have changed the plugs, plug wires and ran a bottle of Sea Foam through it. The plugs and wires made no difference at all. The Sea Foam really helped but did not completely resolve the problem. I actually took it to the dealer and their Sportster Tech worked on it for 3 hours and admitted there was a problem but he could not find it. Does anyone have a idea what could be wrong? The bike has posted no codes and the fuel air mixture off a dyno is constant at low and high speeds. Oh yes, I have checked the blinker fluid and greased the muffler bearings. Any help would be appreciated.
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Old 09-01-2019, 01:23 PM
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It's the kanewty valve. I would change fuel filter and try some ethanol free gas.
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Old 09-02-2019, 07:09 AM
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That tech, should have his license revoked! Three hours and no better. Any good shop should be able to determine weather its a fuel problem, or and ignition problem in a lot less than three hours. Since the Sea Foam seemed to help, sounds like dirty injectors. Have a real, off the bike injector cleaning and test.
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Old 09-02-2019, 07:41 AM
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Originally Posted by cjschlosshan View Post
... and their Sportster Tech worked on it for 3 hours ...
They have a dedicated Sportster tech?

Sent from here to there.

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Old 09-02-2019, 08:28 AM
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The Tech spent 3 Hours doing what? I hope they didn't Charge you for that. Did you Drain/Replace the Gas? If the SeaFoam helped, it's Fuel System related.
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Old 09-05-2019, 11:58 AM Thread Starter
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Yes I did drain the gas and refilled with 93 octane. The service writer only charged me for the hour he thought was what it would take at the most to find the problem. I am going to run another can of SeaFoam through it and if the problem is still there the next step will be injector cleaning and testing. Thanks for good responses.
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