hi,

So I recently brought an FXR from 89 with an original engine, ignition module, an Accel ignition coil, and a Keihin butterfly carb.
I´m having an intermittent problem.
The bike starts and after one minute with the choke pulled halfway it shuts off.
I check the spark from the ignition coil, touching a flat screwdriver on one of the "exits" and approximating the tip to near the cylinder head, when everything is OK I see multiple sparks coming from the tip of the screwdriver.
But now I see the 1st spark and then I don't get anymore.
If I turn off the ignition and wait a minute I repeat the process and appends the same.
This loss of spark is common when the Harley is cold after I run it for 5 miles it warms up and I never get to any more problems, I think...
The ignition coil is accusing 3.6 ohms and 11800 ohms, in the primary and secondary circuits respectively.
I also some times have gas on the ground and others not, I have clean the carb and adjust the float to the specified gap.
I also check if I have spark when I touch the terminals from the cam position sensor
I have none.
The other day I remove the paint from the ground connection of the ignition control module and the bike run fine I thought the problem has there but now I don't understand.
I have talked to someone and was advised to check the ignition wiring.

Thanks for any welcome help.

 

I would suspect the coil. 3.6 ohm is a little high. Secondary it's good.. with the ignition on check for 12v to the coil (white wire) disconnect the wire on the other terminal and with a jumper wire momentarily ground the coil and release if you see spark your good. If not replace the coil.. here's a video to help you..

 

The 3.6 ohms on the primary is a bit high, but shouldn't cause the problems you describe.

When any ignition system produces a single spark then none, it's because there is a loss of capacitance on the primary circuit. (bad condenser on points or magneto system, ignition module on electronic system) You also mentioned in another thread a problem around 90 (kph or mph?) That could indicate a module malfunction.

If you can get it to run until warm and everything is OK, that is a symptom of a (failing) temperature sensitive pickup in the nose cone.

Since the ignition module is no longer available, many, if not most of us have gone to either an aftermarket ignition module using a stock type cam position sensor, or a self contained nose cone module like the Dyna 2ki, Ultima 53-644, Compufire etc.

If you want to fully diagnose what you have now, go to post #10 and post #27 at this link: https://www.hdforums.com/forum/ignit...-no-spark.html

 

thank's for the help.
I will try later

 

So I did the full diagnosis on post #27 and everything checks. That's great.
I have another Harley, 03 Sportster, and with the coil from that one, I put on the FXR and then it started. AGAIN Great news.
Thinking I needed a new coil...but because the coil has not well secure I had to stop the FXR and rearrange the coil position.
I disconnected the 4 cables( 2 whites from one point and a blue and pink from the other) from the coil reposition the coil and, AGAIN nothing, no spark.
NOTE: The coil I'm using is from my 03 Sportster and never fails on me. really reliable Harley

The coil test.
I left the white 12v connecter on the coil and with a jumper cable to ground I tried to get a spark and nothing, I saw a small spark on the "negative" of the coil when I removed the jumper. but I never saw a spark.

My conclusion is that the White 12v cable that goes to the coil is not ok, sometimes I have power others not.
I have seen that I can bypass it with a jumper cable that feeds 12v from the battery and test again.

Anyway learning a lot about this FXR.

Is there a post with instructions on diagnosing the wiring?

 

Sounds like you have an after market ignition (single fire) Blue and pink wires are triggers from the cam position sensor. Sounds like you might have an intermittent 12v feed. You can always wire the power to the coil direct off the battery but make sure you put in a 10 amp inline fuse and disconnect the old feed. If that cures it then you need to physically trace the white wire back to the source. I suggest you get a Factory Service Manual... Normally wiring goes from the battery to the ignition switch to a fuse then to the kill switch in the handle bars then to the coil. You also need to open the little round cover on the cam chest to see what kind of ignition system you have.. Doesn't sound as if it's stock.

 

My coil is an accel 140405, only has 2 inputs, which I believe is dual fire coil.
My ignition module is the original one, it has the Harley reference number.

Thanks for the idea of the cable with the 10 A fuse.

I have the all the manuals and diagrams.
Later I will give some feedback

 

So your telling me it's a dual fire but you used the coil from you 2003 sporty that had 4 wires. 2 white, 1 blue and 1 pink. sounds like its a single fire coil on the sporty and that won't work on the FXR...

 

BTW my neutral light is somewhat intermittent also, I need to pull the shifter lever up, right until it goes to 2nd in order to light up the neutral indicator light.
I have taken the connector for the switch off and on again, stays the same.

Also, the way I put gears on the FXR compared to the Sportster, seems like I have a lot of room in the shift lever.
The Sportster is a bit hard to find the neutral, I need to give it some gas before I can get to neutral but in the FXR the transmission gives the sensation that it has a lot of Freeplay.

Is this normal behavior for the FXR's transmission? Can I do something about the neutral switch?

 

Maybe a photo will explain my point.
This is what is on my FXR.
The one in the Sportster has the same 2 input, but only one cable goes into each other.