Stumped
Seasoned HDF Member
Joined: Apr 2012
Posts: 9,980
Likes: 5,218
From: Michigan
I had an '87 FXSTC that I tried to convert to the old "points and condensor" ignition system with bad results.
The crankshaft nose (and lobes) were so out of specs that I could not "set" the points at a consistent gap and within a couple of hundred miles they were destroyed!
I finally gave up and removed the ignition module (from the bottom of the horseshoe oil tank) and replaced it---solving the problem.
I learned later on that when the dealers replaced these ignition modules they were relocating them to the top of the rear fender and under the seat to eliminate the heat source that was coming from the heated oil and the rear cylinder and destroying them.
The crankshaft nose (and lobes) were so out of specs that I could not "set" the points at a consistent gap and within a couple of hundred miles they were destroyed!
I finally gave up and removed the ignition module (from the bottom of the horseshoe oil tank) and replaced it---solving the problem.
I learned later on that when the dealers replaced these ignition modules they were relocating them to the top of the rear fender and under the seat to eliminate the heat source that was coming from the heated oil and the rear cylinder and destroying them.
Seasoned HDF Member
Joined: Jun 2010
Posts: 9,332
Likes: 3,873
From: Upstate New York
I had an '87 FXSTC that I tried to convert to the old "points and condensor" ignition system with bad results.
The crankshaft nose (and lobes) were so out of specs that I could not "set" the points at a consistent gap and within a couple of hundred miles they were destroyed!
I finally gave up and removed the ignition module (from the bottom of the horseshoe oil tank) and replaced it---solving the problem.
I learned later on that when the dealers replaced these ignition modules they were relocating them to the top of the rear fender and under the seat to eliminate the heat source that was coming from the heated oil and the rear cylinder and destroying them.
The crankshaft nose (and lobes) were so out of specs that I could not "set" the points at a consistent gap and within a couple of hundred miles they were destroyed!
I finally gave up and removed the ignition module (from the bottom of the horseshoe oil tank) and replaced it---solving the problem.
I learned later on that when the dealers replaced these ignition modules they were relocating them to the top of the rear fender and under the seat to eliminate the heat source that was coming from the heated oil and the rear cylinder and destroying them.
Seasoned HDF Member
Joined: Oct 2007
Posts: 8,852
Likes: 2,493
From: Decatur, Alabama
How many miles you got on that thing? The last time my EVO backfired and wouldn't restart, there was a hole in the piston and the entire motor had to be rebuilt. Mine had 89k on it when she gave up the ghost.
carl
carl
Stellar HDF Member
Joined: Feb 2013
Posts: 3,072
Likes: 1,727
From: Dallas, Texas
Dyna S units have been known to fail, I've replaced quite a few over the years. Get an ULTIMA electronic ignition system, single fire. It's adjustable advance curves will work for any big twin or Sportster. Single Fire will reduce vibrations. Just follow the directions for install AND ya get to remove the stock ignition black box.
Seasoned HDF Member
Joined: Jun 2010
Posts: 9,332
Likes: 3,873
From: Upstate New York
A compression test would verify that pretty quickly.
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jonhoffers
Ignition/Tuner/ECM/Fuel Injection
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Mar 7, 2006 12:20 AM