Touring Models Road King, Road King Custom, Road King Classic, Road Glide, Street Glide, Electra Glide, Electra Glide Classic, and Electra Glide Ultra Classic bikes.
Sponsored by:
Sponsored by:

Compression Release mechanical

Thread Tools
 
Search this Thread
 
Old Jan 14, 2012 | 11:27 PM
  #1  
Ultraman43's Avatar
Ultraman43
Thread Starter
|
6th Gear
Joined: Jul 2009
Posts: 11
Likes: 0
Default Compression Release mechanical

Would like to know the pro's & cons of installing these? Have installed the high compression heads and bike cranks over fine without them.....
 
Reply
Old Jan 15, 2012 | 06:41 AM
  #2  
grbrown's Avatar
grbrown
Club Member
15 Year Member
Liked
Loved
Community Favorite
Joined: Jun 2007
Posts: 45,429
Likes: 2,897
From: Bedford UK
Default

The main pro is they reduce the start-up load on your starter motor. This in turn means there is no need to use a larger starter when making substantial mods to the engine. I don't know of any cons! I have had an S&S engine in my bike for almost 4 years and have automatic CRs, which are fine.
 
Reply
Old Jan 15, 2012 | 06:46 AM
  #3  
troop's Avatar
troop
Outstanding HDF Member
Joined: Oct 2009
Posts: 2,870
Likes: 49
From: Stoughton, WI
Default

One con is over time (carbon build up) is that they can start to stick. Remove, clean with carbon cleaner and brush and re-install...
 
Reply
Old Jan 15, 2012 | 06:55 AM
  #4  
tpb857's Avatar
tpb857
Road Master
Veteran: Marine Corps
15 Year Member
Liked
Loved
Joined: Sep 2008
Posts: 811
Likes: 99
From: Hopewell Twp, PA
Default

I'm on the fence now about whether to get the ACRs or not. On my 09 SG, I am putting the 103 kit stage II kit in. The dealer is going to do the work. The dealer says that I don't need them, but I don't want to have starting problems either. The parts don't seem like they cost that much, but I don't know how much to install them since it looks like some drilling needs to be done.
 
Reply
Old Jan 15, 2012 | 08:42 AM
  #5  
1flhtk4me's Avatar
1flhtk4me
Seasoned HDF Member
15 Year Member
Joined: Apr 2006
Posts: 10,675
Likes: 95
From: Billings,Mt.
Default

Originally Posted by tpb857
The parts don't seem like they cost that much, but I don't know how much to install them since it looks like some drilling needs to be done.
Ask your dealer if they can machine the heads and how much will the labor cost.
 
Reply
Old Jan 15, 2012 | 08:50 AM
  #6  
6 gun's Avatar
6 gun
Seasoned HDF Member
Liked
Loved
Community Favorite
Top Answer: 1
Joined: Mar 2008
Posts: 9,377
Likes: 1,774
From: Central Texas
Default

For what it is worth, unless your compression is jacked
way the heck up I don't think compression releases are
needed I am running 10.5:1 but I have 1.4 kw starter
but, it is over kill. My starter cable rotted into inside the
insulation and I thought my starter had craped out but,
the stock starter was having no problem what so ever
with my 10,5:1 compression.
 
Reply
Old Jan 15, 2012 | 09:03 AM
  #7  
6 gun's Avatar
6 gun
Seasoned HDF Member
Liked
Loved
Community Favorite
Top Answer: 1
Joined: Mar 2008
Posts: 9,377
Likes: 1,774
From: Central Texas
Default

Originally Posted by troop
One con is over time (carbon build up) is that they can start to stick. Remove, clean with carbon cleaner and brush and re-install...
If the manual CR will carbon up over time, will the ACR carbon up as well,
and how hard would they be to remove clean and replace,
just wondering?
 
Reply
Old Jan 15, 2012 | 11:48 AM
  #8  
qtrracer's Avatar
qtrracer
Ultimate HDF Member
Joined: Jan 2008
Posts: 6,532
Likes: 132
From: SoCal
Default

Originally Posted by 6 gun
If the manual CR will carbon up over time, will the ACR carbon up as well,
and how hard would they be to remove clean and replace,
just wondering?
I have had my ACR's installed for 3+ years and I have had no need to remove, clean or replace. Original battery and starter, 195 psi cranking pressure. I would do them again any time I had heads off any bike as they work seamlessly with no operator input and I have had ZERO problems with starting in any way.
 
Reply
HD Forum Stories

The Best of Harley-Davidson for Lifelong Riders

story-0

7 Surprising Harley-Davidson Products that Are Not Motorcycles

 Verdad Gallardo
story-1

8 Best Harley-Davidson Motorcycles Ever

 Pouria Savadkouei
story-2

10 Worst Harley-Davidson Motorcycles Ever

 Pouria Savadkouei
story-3

Killer Custom's Jail Break Is The Breakout That Refused to Blend In

 Verdad Gallardo
story-4

Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?

 Verdad Gallardo
story-5

Harley-Davidson Reveals Super Cool Cafe Racer Concept

 Verdad Gallardo
story-6

Engraved Rebellion: Inside Bundnerbike's Glam Rock II

 Verdad Gallardo
story-7

10 Motorcycles You Should Never Buy

 Joe Kucinski
story-8

10 Things Harley-Davidson Needs to Fix in 2026

 Verdad Gallardo
story-9

Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider

 Verdad Gallardo
Old Jan 15, 2012 | 11:53 AM
  #9  
grbrown's Avatar
grbrown
Club Member
15 Year Member
Liked
Loved
Community Favorite
Joined: Jun 2007
Posts: 45,429
Likes: 2,897
From: Bedford UK
Default

CRs of both types are installed rather like spark plugs, so they can be easily removed for service or replacement. Don't make a mountain of a molehill out of them!
 
Reply
Old Jan 15, 2012 | 12:54 PM
  #10  
bigdaddy33's Avatar
bigdaddy33
Elite HDF Member
Joined: Apr 2009
Posts: 4,082
Likes: 11
From: Long Island, NY
Default

+1 When I went to a 117" in my FXDL, we installed the S&S Manual Compression Releases, with the single **** and it's worked fine.


Originally Posted by grbrown
The main pro is they reduce the start-up load on your starter motor. This in turn means there is no need to use a larger starter when making substantial mods to the engine. I don't know of any cons! I have had an S&S engine in my bike for almost 4 years and have automatic CRs, which are fine.
 
Reply
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
hd0wner
Touring Models
120
May 24, 2011 12:32 PM
tbusa
Touring Models
11
Nov 24, 2010 09:08 PM
oscarg
Touring Models
22
Jan 7, 2010 07:47 AM
dlrshort
Exhaust System Topics
5
Oct 12, 2009 09:51 AM
paco ritter
Touring Models
52
Feb 19, 2009 09:29 PM




All times are GMT -5. The time now is 12:21 AM.

story-0
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-1
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-2
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-3
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-4
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-5
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-6
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-7
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-8
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
story-9
Southpaw Super Glide: A Left-Hand-Drive 1979 Harley FXE Built to Fit the Rider

Slideshow: Graeme Billington's left-hand-drive Shovelhead is as much about problem-solving as it is about classic Harley form.

By Verdad Gallardo | 2025-12-30 11:27:08


VIEW MORE