Shovelhead A place to talk about Shovelheads.

Stock 1981 electronic advance question

Thread Tools
 
Search this Thread
 
Old Sep 3, 2017 | 04:19 PM
  #1  
dofiss's Avatar
dofiss
Thread Starter
|
6th Gear
Joined: Aug 2010
Posts: 10
Likes: 0
From: Southwest Florida
Default Stock 1981 electronic advance question

Buddy has an 80" 1981 FXR with stock HD electronic ignition but no damn shop manual (now on order). There's no mechanical advance or VOES switch. I'm an old shovelhead guy and now have a blockhead so I'm wondering how they advance the timing? Is it done by reading the rpm's as a tachometer would? We're changing to new electronic ignition and adding a VOES for advance but I've never played with one of these. Thanks much. Dofiss
 
Reply
Old Sep 4, 2017 | 08:08 AM
  #2  
mrlexus's Avatar
mrlexus
Road Captain
15 Year Member
Photogenic
Photoriffic
Top Answer: 1
Joined: Jan 2007
Posts: 645
Likes: 216
From: Minneapolis
Default

It advances by the rpm, just like points and every other electronic ignition do. The VOES just gives a signal to the ignition module to retard timing during low vaccum situations, same as a vacuum advance on a car.
 
Reply
Old Sep 4, 2017 | 01:17 PM
  #3  
dofiss's Avatar
dofiss
Thread Starter
|
6th Gear
Joined: Aug 2010
Posts: 10
Likes: 0
From: Southwest Florida
Default Not sure you understand my question.

I understand how a mechanical advance works as well as a VOES advance. This HD has neither which makes me ask how does it know the rpm's are increased?
I've been the sole mechanic on my HD's for 50 years now but am unfamiliar with this particular electronic system and how the advance works. My assumption is that this ignition advances by reading the RPM's directly to the electronic unit as opposed to a VOES or mechanical advance. We're adding a VOES for the new system but I mistakenly assumed it already had one being void of a mechanical advance, which proposed the question, how does it know?
Thanks for your response.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Uzzah
EVO
11
Mar 22, 2017 01:27 PM
ratz
Ignition/Tuner/ECM/Fuel Injection
4
Apr 3, 2013 04:43 AM
jimjam31
EVO
15
Jan 26, 2012 08:43 PM
RidemyEVO
EVO
18
Jun 16, 2011 07:32 AM
Daveloba
Sportster Models
1
Apr 11, 2009 03:19 PM




All times are GMT -5. The time now is 02:58 PM.

story-0
7 Times Harley-Davidson Chucked Tradition Out the Window

Slideshow: Harley-Davidson built its reputation on nostalgia, but every so often, the company took a hard left turn into the future.

By Verdad Gallardo | 2026-05-20 11:18:19


VIEW MORE
story-1
7 Surprising Harley-Davidson Products that Are Not Motorcycles

Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.

By Verdad Gallardo | 2026-04-29 16:50:35


VIEW MORE
story-2
8 Best Harley-Davidson Motorcycles Ever

Slideshow: Not every Harley gets it right, but these are the ones that genuinely earned their reputation.

By Pouria Savadkouei | 2026-04-15 14:23:21


VIEW MORE
story-3
10 Worst Harley-Davidson Motorcycles Ever

Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.

By Pouria Savadkouei | 2026-04-01 20:01:09


VIEW MORE
story-4
Killer Custom's Jail Break Is The Breakout That Refused to Blend In

Slideshow: Killer Custom's "Jail Breaker" build focuses more on stance and visual aggression than mechanical overhaul.

By Verdad Gallardo | 2026-03-18 19:20:32


VIEW MORE
story-5
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?

Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.

By Verdad Gallardo | 2026-03-07 16:15:30


VIEW MORE
story-6
Harley-Davidson Reveals Super Cool Cafe Racer Concept

Slideshow: Harley-Davidson's new RMCR concept revives the café racer formula with modern hardware-and it may be exactly the reset the company needs.

By Verdad Gallardo | 2026-03-04 12:23:37


VIEW MORE
story-7
Engraved Rebellion: Inside Bundnerbike's Glam Rock II

Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.

By Verdad Gallardo | 2026-02-24 18:19:44


VIEW MORE
story-8
10 Motorcycles You Should Never Buy

Slideshow: There is no shortage of great motorcycles to buy, but we would avoid these ten.

By Joe Kucinski | 2026-02-19 14:50:51


VIEW MORE
story-9
10 Things Harley-Davidson Needs to Fix in 2026

Slideshow: Harley-Davidson's challenges aren't abstract; they show up in dropping shipments, shrinking dealer traffic, and strategic decisions that aren't yet translating into growth.

By Verdad Gallardo | 2026-01-13 18:33:17


VIEW MORE