1998 FLSTF dies randomly

[TKO]

I recently bought a very low mileage 98 Fat Boy. I've put almost 1k on it in the last 3 weeks. The bike runs perfectly... most of the time. 3 or 4 times now, it has momentarily shut off while at speed. It acts like it's out of fuel even though the tanks are full. Then, just as quickly as it die, it fires right back up and runs perfectly for another 150 to 200 miles. Twice now it has died, again, as if it had no fuel or the ignition was shut off but, on these occasions, it did instantly fire right back up. Instead it left me scratching my head on the side of the road. Both times the bike started again after 10 to 25 minutes. The new peacock, new fuel line and carburetor newly cleaned by me leads me to believe this is not a fuel issue. I  think it may be an ignition issue. This bike still has the original electronic ignition. This is the newest road bike I have ever owned and it's the only bike I've ever owned that has an electronic ignition. If it had points, I wouldn't have any questions. Unfortunately, I know absolutely nothing about electronic ignition. Could this be a bad ignition?

Any information would be greatly appreciated. 

Thanks 

[rigidthumper]

Pull the points cover, and take a look at the cam position sensor. If it appears to be burnt, gooey, or melted, like this one, that's most likely the culprit. 



Part Number is 32448-95B

[Tacocaster]

There's still some detail left out that would help. Are you losing "everything" including Lights perhaps?

Otherwise it sounds like possible vapour lock (gas cap not venting) but consider heat as well. Examine the main breaker to ensure it's not in a "hot spot" where it's subjected to a heat source (such as the oil tank).

[HogMike]

I recently bought a very low mileage 98 Fat Boy. I've put almost 1k on it in the last 3 weeks. The bike runs perfectly... most of the time. 3 or 4 times now, it has momentarily shut off while at speed. It acts like it's out of fuel even though the tanks are full. Then, just as quickly as it die, it fires right back up and runs perfectly for another 150 to 200 miles. Twice now it has died, again, as if it had no fuel or the ignition was shut off but, on these occasions, it did instantly fire right back up. Instead it left me scratching my head on the side of the road. Both times the bike started again after 10 to 25 minutes. The new peacock, new fuel line and carburetor newly cleaned by me leads me to believe this is not a fuel issue. I  think it may be an ignition issue. This bike still has the original electronic ignition. This is the newest road bike I have ever owned and it's the only bike I've ever owned that has an electronic ignition. If it had points, I wouldn't have any questions. Unfortunately, I know absolutely nothing about electronic ignition. Could this be a bad ignition?

Any information would be greatly appreciated.

Thanks

Check the wire coming from the cam sensor and trace it back to the ignition module.
My bike had a metal clamp along the wire that was not installed properly and was pinching the wire. Dealer never found it under warranty and ordered a whole new ignition system.
I fixed the wire and clamp and the stalling and ignition problems went away.
Still have the original replacement parts somewhere in my parts stash!
Worth a check anyway.
Good luck.

[Hossamania]

Check your battery terminals.

[calif phil]

Another thing to check is the connector at the ignition switch or the switch itself. Try lightly wiggling the switch and wiring whilst running and see if you can make it shut off. Looks for tell tell signs of green corrosion.   

[fbn ent]

It is also possible that the kill switch is the culprit although the low mileage may rule that out. Again, do you lose all power when it raises it's ugly head?

[SP33DY]

Here are two more things I have encountered causing this type of problem.
 First is a fuel cap that is not venting. I've seen it a lot on older Softails. When the engine starts to falter, unscrew the cap and see if it clears up.
 The other thing is having some water in the fuel. If you bought gas while the tanker is dropping fuel at the gas station or shortly afterwards, it's not unusual to get contaminated fuel. The fuel drop process stirs up all the crud and water that was laying in the bottom of the storage tank.
 There is one gas station in my neighborhood where I absolutely will not buy gas. I have had fuel problems more than once after buying gas there. I don't think they maintain their tanks.

[TKO]

Well,  I checked the battery terminals. They were good and tight, the cables are good and the ground strap is tight to the frame. 

I wiggled the ignition switch and connections with no results. 

Then I drilled the rivets out of the cam cover so I could take a look at the non points system inside. To my surprise, there wasn't a cam position sensor like Rigidthumper showed. Instead, I found what I believe is an electronic ignition module. I will post a photo if I can figure out how to do that. 

It may be possible that it's a tank venting issue but, just a few days ago,  I this bike at 70mph for more than 2 hours trying to get an ideal of fuel mileage (37mpg) with no issues. I would think it would have choked at that time if it were a vent issue. However, it does have what I believe to be aftermarket caps so, I guess it is possible. 

[TKO]

Pull the points cover, and take a look at the cam position sensor. If it appears to be burnt, gooey, or melted, like this one, that's most likely the culprit. 



Part Number is 32448-95B

Photo
You cannot view this attachment.

[TKO]

Pull the points cover, and take a look at the cam position sensor. If it appears to be burnt, gooey, or melted, like this one, that's most likely the culprit. 



Part Number is 32448-95B

Photo
You cannot view this attachment.

This is what I  found lol

[Tacocaster]

70+ for 2 hours? Doubtful it's a gas cap venting issue but stranger things have happened.

My personal experience has shown the Compufire Ign. can and will fail but it won't kill "everything". So again, in the interest of clarification, when the engine dies do you still have lights and all running electrics alive?

Why? you might be asking. Because a mains failure will shut down an engine quickly but it also takes "everything" else down as well and self-recovery after a few minutes can be typical of some breakers when affected by heat.

A consideration to note, your Compufire may be expanding from engine heat and opening the trace on the printed circuit board when it expands (bends). I had a taillamp circuit board do that on my 07.

Wonder if the previous owner ever experienced this issue?

[FSG]

This is what I  found lol

CompuFire Elite 1

[TKO]

70+ for 2 hours? Doubtful it's a gas cap venting issue but stranger things have happened.

My personal experience has shown the Compufire Ign. can and will fail but it won't kill "everything". So again, in the interest of clarification, when the engine dies do you still have lights and all running electrics alive?

Why? you might be asking. Because a mains failure will shut down an engine quickly but it also takes "everything" else down as well and self-recovery after a few minutes can be typical of some breakers when affected by heat.

A consideration to note, your Compufire may be expanding from engine heat and opening the trace on the printed circuit board when it expands (bends). I had a taillamp circuit board do that on my 07.

Wonder if the previous owner ever experienced this issue?

I haven't riden it at night and I didn't check to see if the lights were still working. The first time it died, the bike cranked over but wouldn't fire. This was on the ride home after I bought it. It was pouring rain and the wind was gusting 60mph. It died about 1 hour in and I thought it might be something electrical ha ing issues with all the water. My son was following in .y truck a d I had a can of fuel in the back so, just to make sure it wasn't out of fuel,  I put a little less than a gallon in.  I was afraid to keep the cap off a y longer because of the torrential rain. After 5 minutes or so, it fired up and ran perfectly for over a week. The 2nd time was dry and cool and it died about 40 minutes into the ride. I got stopped and checked the position of the peacock out of habit, then tried the starter and it fired back up and ran perfectly for the 40 minute ride back home.

I don't know if heat is an issue as the warmest temperature I have ridden in so far is the low 70s with most rides being in the 60s and even high 50s.
This electronic stuff stumps me.  I have no experience working with this type of ignition.
I bought this bike as a donor for an Evo chopper project. I never expected to like it as much as I do. I'm really hoping to get the bugs out by next week as I have 2 weeks off and I would like to take a trip on this thing instead of tearing it completely down like I originally intended.

[crock]

Try going for a ride with the cover off. If it's heat related it may help solve it. I had a Crane HI4 go bad but spent months chasing fuel gremlins because I just knew it was running out of gas. And now I run points. With points they either work or they don't

[Tacocaster]

Appears heat is likely not your culprit either. I think you've reached the "get down on your knees and pray" - I mean, closely inspect the various wiring points where these culprits tend to hang-out. Recommend a good HD service manual for the wiring schematics -  likely can source the schematics on-line for an older ride by now. Where you have a 26 yr old, don't overlook cleaning the Grounding points for corrosion.

Calf Phil noted the ignition switch up on your tank. That's yet another source of gremlins many folks have experienced. As well Hogmike, Speedy and fbn ent have provided possibilities you can verify.

An added benefit to all your efforts is the "getting acquainted" aspect of your new ride when going this route. You'll thank us later.

Short of that, where the issue is so intermittent, you just may be up against the expensive route - the Ignition (Compufire or other quality item) entirely driven by blind parts replacement followed by coil(s), followed by, (Yes, coils can be tested first) Ignition Switch, followed by.....

Any issue with contacting the previous owner to determine history? Be nice and he might open-up. 

[Hossamania]

The ignition switch can be disassembled (carefully on a tray so as not to lose small pieces) and cleaned. It is pretty simple.
Is it still a vacuum operated petcock? Is so, does it have a new vacuum line? Have all vacuum lines been inspected/replaced? Personally I am a fan of mechanical petcocks like Pingel.
Next time it dies, try starting with some carb cleaner or starting fluid sprayed directly into the carb. That should point to fuel or ignition.

[calif phil]

If the lights stay on when it dies, it's time for a new ignition.  I like the Daytona Twin Tec or the Dynatec.

You can try and warm up the ignition module in your picture with the ol lady's  hair dryer while the bike is running, if it dies, you found the culprit.  Not a 100% test, but doesn't hurt to try. 

[speedzter]

Taco mentioned it , but does your bike have plug in circuit breakers fitted ?
Show us a photo of the setup .

[TKO]

Taco mentioned it , but does your bike have plug in circuit breakers fitted ?
Show us a photo of the setup .

I don't know about breakers, but it does have the black plastic box mounted under the seat in the rear fender.

.My plan for tomorrow is two fold.
1. I'm going to put the fuel line from the carb and drain the tanks with the caps secured. The tanks are full and this should tell me definitely whether I have a venting issue. 
2. I am going to get some dielectric gel and go over all the plugs and connections to include the ignition and kill switches. Also, I discovered the neutral safety switch does not work. (Glad I was sitting on it at the moment of discovery)

I will probably check the coil with my multi meter too.

I can tell you this much for certain. I wish I had a lift! 57 years of crawling around on my hands and knees is getting REALLY old lol!

I'll try to get some photos of the electrical stuff when I get home. 

Thanks to all for the info and suggestions. 
I sincerely appreciate your time and consideration. 

[fbn ent]

 "I wish I had a lift!"

Treat yourself. You won't regret it!

BTW, I don't think '98s had a neutral safety switch...my '02 doesn't.

[Hossamania]

Correct, no neutral safety switch switch.
Is the petcock vacuum operated or aftermarket non vacuum?

[kd]

TKO, do you have or access to a genuine Harley Factory Service Manual.  Following this thread I feel it is the one thing that will help you the most.  It will include the test parameters you need and which breakers and fuses or contact points you need to test.

[TKO]

Correct, no neutral safety switch switch.
Is the petcock vacuum operated or aftermarket non vacuum?

No neutral safety switch. Got it.

The petcock is just a regular off/on/reserve style screwed into the bottom of the left side tank. The fuel line is the only line coming off of it.

[TKO]

TKO, do you have or access to a genuine Harley Factory Service Manual.  Following this thread I feel it is the one thing that will help you the most.  It will include the test parameters you need and which breakers and fuses or contact points you need to test.

I downloaded the manual for multi year softtails from Lowbrow last night right before bed which was extremely late as my oldest son and I were out watching the northern lights that were visible here in Kansas last night. I haven't even opened that download yet.