I experienced a recurring, but intermittent, problem with my 2004 Dyna WG where the engine would abruptly shut down, cut off, or stall while driving on the road, occasionally while shifting gears, and once it happened during a turn! Very disconcerting to say the least!

It was due for a 10K service, so I took it to the local HD dealership and explained the symptoms as well as my concern about it. After keeping it one day and performing the scheduled maintenance, I was informed that they could not reproduce the engine stalling problem and, despite my protestations about the danger involved, there was nothing more they could do for me and, without actually saying it, it felt to me as though the Service Manger suspected "user error."

At that point, I went searching for another motorcycle shop and, thanks to this forum, found Scalia Cycles (Fairfax, VA). After explaining the problem, they said, "Ah, that issue is often caused by a bad temp sensor. Bring it in and we'll gladly troubleshoot it for you." Scalia had the bike for just under a week. Their mechanic was able to reproduce the problem on a diagnostic ride, narrowed the cause to a bad engine temperature sensor ($43 part), replaced it, and test rode it for another 25 miles without incident. I have since put another 50 miles on the bike and, so far, the problem has not recurred!

In my research of this problem, I managed to capture a list of oft-cited causes of engine stalling and wanted to get them listed in one document in case another HD owner runs into it. If nothing else, it might save someone the many hours I spent devouring posts across several forums. The items are generally listed in the order most frequently mentioned:

Fuel/Air

• Pinched vaccuum lines
• Fuel Pump can fail when hot, but run fine when cool
• Fuel tank breather clogged or venting problem
• Idle Air Control (IAC)
• Fuel Pressure Regulator (FPR)
• Gas cap

Electrical

• Battery connections loose (esp. negative/ground)
• Ground cable bad
• Crank Position Sensor (CKP)
• System Relay sensor
• Kill switch on throttle side
• Ignition switch
• Kickstand position sensor
• Bank angle sensor
• Ignition Coil
• Throttle Position Sensor
• Wiring harness: vibration causing intermittent failure (ground)
• Capacitive Discharge Ignition (CDI)
• Voltage Regulator
• Stator
• Temp Sending Unit can fail when hot, but run fine when cool
• Speed sensor sending out irregular signals

I find it curious that "Engine Temp Sensor" is not among the listed causes above although maybe it is shown under a different name. In my own case, that item turned out to be the culprit!

Ken

 

yep, i am having the same problem with my custom,,,doesnt matter wheather its hot or cold, 1 mile from the house or 30, as if i hit kill switch. by the time i get pulled to the side of the road, hit the start button, and off we go,,,but ive had it do it 2 to 3 times within a city block,,,do you know where the engine sensor they changed was located..? id appreciate any advice,,,and thanks for posting the list,,,

 

I would add bad or wrong gas to the list. My GF accidentally put 87 octane in her 2011 Heritage and it wouldn't idle, died at every stop, until topped off a couple times with 93 octane. No codes ever showed.

 

i only burn premium in mine , or it does run like sh#t,,,today i metered my fairly new coil, and was getting some wacky readings while running , and ran the throttle till it shut down,,,ckd the breakers and they flatlined for about 20 seconds , then clicked and were back at 12.7 or so ,,,start it up and run again,,,did that about 4 times,,,,then i took a jumper wire from positive post on battery to bottom post of my coil,,,(has two wires on it,other has one),,,fired her up and ran the throttle till i finally had to shut the bike down myself,,(by pulling the jumper wire,). Now , i think that should tell me that my voltage regulator is bad.....right?

 

Went on a 1100 mile run this weekend. After a long duration i experienced this exact problem. I googled this and found this thread GREAT INFO

 

Engine temp sensor on twin cams is located on the back side of the front cylinder heads, behind the horn cover. You need a 3/4" deep well socket and a ratchet to remove it after you remove your horn.

Another thing that can cause a bike to stall is a leaking intake seal.

 

Road, sounds like she got bad gas. Going to 87 from 93 shouldn't make the bike stall or run bad, maybe ping a little.

The case with the newer fuel injected bikes is usually the IAC and also could be what Harley tuner posted about the intake seal.

Great post.

 

I've had a lot of bad speed sensors over the years as well. That usually causes the bike to stall while coming to a stop though. If the speed sensor is bad when the bike gets under 5 MPH or so the sensor can tell the ECM that the bike is stopped and it will open the IAC, since the butterfly is still open it will go way lean and stall the motor. Some other symptoms of a bad VSS can be that teh turn signals do not automatically cancel.

 

I am having the same problem. My problem is definitely electrical not fuel/air. Its as if I hit the stop switch. The engine dies (even the dash goes dark) then it comes back on the fly by itself. Its only completely died (requiring me to pull over) one time.
Checked the neg connection at the battery, I got an 1/8 turn on it nothing crazy. I went for a 5 mile ride with no problems. Still not sure if its a fix or not since the problem is intermittent (1 time last week and 3 times in 10 miles two days ago).
Of course im planning a long ride next weekend and im paranoid as he11

 

What year and model is your bike? Older touring bikes had a auto reset circuit breaker that would do exactly that. There was a service bulletin that had the dealer replace the circuit breaker with a larger one. I beleive they were '04 and older touring bikes.