Is there anyway to check if the ignition module is bad? My coil is good as I have no issue with spark. When the bike heats up its starts sputtering and backfiring really badly. I already pulled gas tank, flushed it, got a new petcock and filter and installed in line filter, and rebuilt the carb. This was all just because it needed to be done anyway, but I don't think its a fuel issue. Ive done a ton of research and a lot seem to be pointing at the ignition module but I can't spend the money till I'm sure. Any help?

Also, if I do deem this thing bad, would it be worth it to just upgrade the module and the coil to a better aftermarket and change from single fire to dual fire?

The bike is a 96 Road King with 16k miles full stock engine fully custom body. I am not very mechanically driven so layman terms would be wonderful. Also any suggestion of places to buy parts or what aftermarkets to upgrade to would be awesome too. Thanks in advance.


The longer story I was trying to spare was the issue started while in traffic waiting to get into a county fair. I waited in traffic too long and it over heated without any tings or pings and the bike died. Walked the bike to a safe lot and walked the rest of the way. After being at the fair for awhile walked back up, bike started to problem. Got about 4 miles into town and the bike started backfiring and sputtering like all hell. Got a ride home a few towns away went back the next day and carted it home. Thought for sure it was carb or fuel issue, fixed what I thought it might be because I had it running in the shop trying to really get it hot and it was running fine after 20 minutes of high revs and idle time, took off into town about 4 miles or so and died in town again. Sat there an hour to let it cool off, started back up and drove like hell back home. That was June of 2016 and I am just now getting back to it because I'm scared like hell to work on it myself but even more afraid to pump hundreds of dollars to a shop just for diagnosis.

 

I had bad sparkplugs do the same thing. I just kept thinking it cant be the plugs because it runs good when cold.

 

That would be odd and would also confuse me. I have changed and checked my plugs and even the resistances of the boot and plug wires. All checks were good. Granted they were tested after a startup but I wouldnt say the bike was hot yet. Thanks for your suggestion and it may be something I need to look into again. I found a way to check by carrying a third plug with you and then pulling the boot from a mounted plug, put it on the third plug and try to start it after its hot to see if you keep spark. I would hate to put the bike all the way back together and then it still end up being what i think the culprit is and then have to take it all apart again.

 

You may want to check the cam position sensor located in the nosecone. Usually when these go bad they will drip brown goo below the nosecone. One test is to start the bike and hit the nosecone with a hair dryer to see if you can replicate the issue. How many miles you have on the bike, and is it carbed or EFI?

 

It is carbed and has 16K miles on it. it does have a bit of grime on the ignition module cable that is coming form the cone. I assumed it was road grime or condensation from sitting since my last ride. I took the cover off of the cone and removed the plate. I should have done the heat gun test while I had it put together but currently I have it stripped down so no carb or tank or battery.

 

I don't see that you checked the gas cap vent.

 

Hey bwoltz that was actually one of the first things I did check when I first had the issue. When I was looking up my symptoms that was one of the first things they said to look at and everything checked out in that respect. Thanks for the suggestion.

 

I only brought it up as you didn't mention it.. I would lean towards the cam sensor as others have said.. Heat gun idea is good.. You could also take it for a ride and use freeze mist when it dies..

 

Try going here:
https://serviceinfo.harley-davidson....cle/lookupForm#
Top right of page - click on search
Enter "1996 Wiring" in search box
Select #1 - Wiring Diagrams & Electrical Troubleshooting
Go to page #35 (page 39 of 332) - Ignition Systems Carbed

 

I am definitely going to look at this. What an awesome suggestion for anything. I wish I knew this existed forever ago.