Low idle Harley sound
Seasoned HDF Member
Joined: Jul 2007
Posts: 6,336
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From: SW Minnesota
The tradional Harley "po-ta-to po-ta-to" sound at idle was due to the old dual fire ignition, when unburned gases in the exhaust pipe were ignited by the "wasted" spark, as both plugs fired at the same time. With EFI, all Harleys now have single fire ignition (each plug fires independently of the other). We now have a "po-tate po-tate" sound.
The Evo's had EFI before the TC , they idled at 1000 ~ , story back then was as I recall to keep the charging system up at a proper level and to provide enuff fuel pressure ..
I had an Evo that I changed over to single fire and couldnt tell that much difference in the idle sound ..
I had an Evo that I changed over to single fire and couldnt tell that much difference in the idle sound ..
Road Master
Joined: Jul 2007
Posts: 792
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From: Niagara Falls, NY
Delphi efi needs around 1000 rpm +- a few to properly run. Had an carbed EVO and ran it around 900-950 rpm. Not bad soud, but after compression and a nice woods cam it woke her up. Too low rpm and you are starving the engine oil. Put some cams in it and wake her up.
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Tourer
Joined: Jul 2007
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From: Central Arizona
The tradional Harley "po-ta-to po-ta-to" sound at idle... With EFI... We now have a "po-tate po-tate" sound.
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Road Master
Joined: Dec 2007
Posts: 889
Likes: 1
From: Long Island, New York
Yup...I miss it in my 08. My Wide Glide and the wife's Sporty are carbed and have the " potato" sound. I guess this is what some would call the future of Harley's? Start looking for the sales on motorcycle anti freeze now. I was wondering why they changed the rake on the 09's. You know you could fill up that added space between the frame and the wheel with a radiater. What do you think? Next year or what?
Outstanding HDF Member
Joined: Apr 2008
Posts: 3,140
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From: Wisconsin
The tradional Harley "po-ta-to po-ta-to" sound at idle was due to the old dual fire ignition, when unburned gases in the exhaust pipe were ignited by the "wasted" spark, as both plugs fired at the same time. With EFI, all Harleys now have single fire ignition (each plug fires independently of the other). We now have a "po-tate po-tate" sound.