Shovelhead A place to talk about Shovelheads.

What spark plugs and gap for a 73 FLH

  #1  
Old 09-05-2015, 05:16 PM
tpb857's Avatar
tpb857
tpb857 is offline
Road Captain

Thread Starter
Join Date: Sep 2008
Location: Pittsburgh, PA
Posts: 730
Received 75 Likes on 54 Posts
Default What spark plugs and gap for a 73 FLH

I know that this this covered in the manual, but I don't know if my bike is stock. The motor is stock, but it has an electronic ignition. What are the right plugs and gap for this set up? Thanks.
 
  #2  
Old 09-05-2015, 05:36 PM
johnjzjz's Avatar
johnjzjz
johnjzjz is offline
Seasoned HDF Member
Join Date: Nov 2006
Location: la la land jerzey
Posts: 12,265
Received 4,522 Likes on 2,865 Posts
Default

as many different ignitions that are available that is a tuffy - picture up whats in the nose cone and many can and will answer to what you have and what would work

you will need a bit more info for a good answer
 
  #3  
Old 09-05-2015, 08:41 PM
Tee&Vee's Avatar
Tee&Vee
Tee&Vee is offline
Stellar HDF Member
Join Date: Jul 2011
Location: Boston, MA
Posts: 2,545
Received 94 Likes on 82 Posts
Default

With electronic iggy I would buy Champion RN12YC and gap to .040
This is a steady combination that works for me but please check this as due to further research, thanks John, the plug maybe too long.
This worked in one of my previous Evos and in a friend's bitsa Shovel that is titled as a seventy five but may not be.
 

Last edited by Tee⋁ 09-05-2015 at 09:21 PM.
  #4  
Old 09-06-2015, 08:10 AM
tpb857's Avatar
tpb857
tpb857 is offline
Road Captain

Thread Starter
Join Date: Sep 2008
Location: Pittsburgh, PA
Posts: 730
Received 75 Likes on 54 Posts
Default

Originally Posted by johnjzjz
as many different ignitions that are available that is a tuffy - picture up whats in the nose cone and many can and will answer to what you have and what would work

you will need a bit more info for a good answer
Here is a picture of the ignition.
 
Attached Thumbnails What spark plugs and gap for a 73 FLH-image.jpg  
  #5  
Old 09-06-2015, 09:26 AM
sqdealgeorge's Avatar
sqdealgeorge
sqdealgeorge is offline
Road Warrior
Join Date: Dec 2007
Location: Eagle River WI
Posts: 1,854
Likes: 0
Received 17 Likes on 17 Posts
Default spark plugs for elect igns

I run Bosch platinums again .040 gap short reach plug #4236 they also have long reach for later shovels/EVOs
 
  #6  
Old 09-06-2015, 01:29 PM
tpb857's Avatar
tpb857
tpb857 is offline
Road Captain

Thread Starter
Join Date: Sep 2008
Location: Pittsburgh, PA
Posts: 730
Received 75 Likes on 54 Posts
Default

I pulled the plugs. They are Accel 437s. The threaded part is much shorter. Does that mean that some engine work was done on the bike? Parts store didn't have them and the cross reference was the one with the longer thread. The plugs were a bit dark from running rich. I went down a size on the main jet in the S&S E, cleaned the plugs off and put them back in. I have no clue on what to do with replacement plugs. Any ideas? Thanks.
 
  #7  
Old 09-06-2015, 03:30 PM
sqdealgeorge's Avatar
sqdealgeorge
sqdealgeorge is offline
Road Warrior
Join Date: Dec 2007
Location: Eagle River WI
Posts: 1,854
Likes: 0
Received 17 Likes on 17 Posts
Default 73 shovels

These were the days of the heads with shorter spark plug depth Accels plugs were never my favorite I love the Bosch platinums
 
  #8  
Old 09-06-2015, 05:13 PM
johnjzjz's Avatar
johnjzjz
johnjzjz is offline
Seasoned HDF Member
Join Date: Nov 2006
Location: la la land jerzey
Posts: 12,265
Received 4,522 Likes on 2,865 Posts
Default

you need to get the date codes off the heads and or picture the numbers up so we can tell what heads you have - a long plug in a short head hits the piston and a short plug in a long head carbons the lower threads up and the engine wont run correctly the entire time they are in it
 
  #9  
Old 09-07-2015, 06:25 AM
tpb857's Avatar
tpb857
tpb857 is offline
Road Captain

Thread Starter
Join Date: Sep 2008
Location: Pittsburgh, PA
Posts: 730
Received 75 Likes on 54 Posts
Default

Originally Posted by johnjzjz
you need to get the date codes off the heads and or picture the numbers up so we can tell what heads you have - a long plug in a short head hits the piston and a short plug in a long head carbons the lower threads up and the engine wont run correctly the entire time they are in it

Where would I find the date codes?
 
  #10  
Old 09-07-2015, 06:37 AM
johnjzjz's Avatar
johnjzjz
johnjzjz is offline
Seasoned HDF Member
Join Date: Nov 2006
Location: la la land jerzey
Posts: 12,265
Received 4,522 Likes on 2,865 Posts
Default

Originally Posted by tpb857
Where would I find the date codes?
i will picture up the different numbers today and post them
 

Thread Tools
Search this Thread
Quick Reply: What spark plugs and gap for a 73 FLH



All times are GMT -5. The time now is 12:45 AM.