I have a 99 FLHTC which is a carburetorated model. the bike runs fine until it gets hot at which point the check engine light comes on and engine quits.
I fixed a bunch of things that I thought might have been contributing but it didn't make a difference.
- replaced exhaust gaskets
- pulled the tank and cleaned it
- pulled the fuel value and cleaned it
- replaced the fuel value
- pulled the carb and cleaned it.

I thought it could have been the heat sensor that is in the forward head, but when I looked it was not there. I called my local repair shop and they told me that is on the fuel injected models.
They indicated it could be a cam shaft sensor.
Any one have suggestions on what I can look at next?
I was not sure how to test the cam shaft sensor.
This is a commuter vehicle for me for 10 months of the year or till snow is on the ground, so it is in all kinds of weather.

Thank You!

 

If the engine light comes on, you should check to see if there are any fault codes.

 

so there lies the problem. The bike just has the old analog instrumentation and I don't own a meter that I can plug in. I need to get it to the repair shop, however i would need to trailer it or have it towed. The repair shop I used to use was 4 miles from my house and all down hill but they unfortunately went out of business .

Thanks!

 

This may be the answer from another forum:

Here's how you pull codes on a 99 FLT. I don't have the list of codes though. Sold the '99 I had a few years ago. You could also do yourself a big favor and get a HD 1999 FLT service manual. All this type of info is in there.

TROUBLE CODES

If the Check Engine Lamp stays off for only 4 seconds and then comes back on for an 8 second period, then a functional error is stored (although no current trouble code exists). A functional error indicates an internal problem with the ignition module (trouble codes 52 thru 55) or with the crankshaft or camshaft sensors/timing (trouble code 56).

If the Check Engine Lamp remains on beyond the 8 second period, then a current trouble code exists.

Using a jumper wire in the diagnostic port connector, between the black wire (terminal 2)and the light green with red tracer wire (terminal 1). Jump them and then turn on the system, and the codes will flash out. If there is just a really rapid flashing too fast to count, that's the 'intermission', the marker between the repeated sets of codes, and if that's all you get, then there are no codes in the system. The only way to clear the code is to connect the scanylizer or it will clear itself after 50 trips.

Be sure the engine run switch is ON (right handlebar), then turn the ignition switch ON. Wait approx 10 seconds (4 seconds lamp ON, 6 seconds lamp OFF). The lamp will then flash one or more times to indicate the first digit of the trouble code. The length of time the lamp is illuminated and the length of time in which it is off are each about 0.5 seconds in duration. There will be a 1.2 second pause following the transmission of the first digit. If there is more than one code, there is a 3 second pause in which the lamp is off. Once all codes have been sent, the data string is repeated. When you have recorded the same trouble code twice, it is an indication that the transmission has been restarted and all trouble codes have been retrieved.

 

Hi CoolBreeze3646,
Thank You for these procedures, I actually do have the FLH service manual, but didn't find it in there.
I have been running this bike 2004, I put a lot of miles on it up till covid, so the last 4 or 5 years the mileage has been.
I will give this a try.

Thanks Again, Happy and Safe Riding!

 

Try changing the big main fuse. The older bikes had problem with them, so dealers cure was to installed a bigger fuse. I did on my old '05 Road king and never had the problem again. The other thing to look at is the coil. They have a habit of crapping out when they get old. They don't like heat.,,,

 

One thing to note. I believe that you can only read historic codes to the HD diagnostics.. IIRC @Ed Ramberger knows for sure..

So it runs after cool down?

For most things you need a DVM.
The quit can be 4 things. Either the crank sensor, cam sensor, coil or ignition module. The problem is that if it has to be hot to fail you may have trouble finding it.. When cool the cam sensor will put out a pulse that you can measure and you can check it with a DVM for levels and toggling but I'm not sure what the levels will be.. The crank sensor can be checked with a voltmeter set to AC and then motor cranking. I guess it could possibly be the bank angle sensor but I'd suspect that it would be less heat related and more bump related..

 

If I remember correctly the 99 can fail a cam sensor when running and it will continue to run - but it cannot find phase and start if it is failed and you try to start it.

On the 99 there is a connector on the bottom of the frame (air cleaner side I believe) that they ran a 12v power and sensors through. It is very common for that to get dirty or wet and have voltage bleeds. the 12V power should be depinned and run separate from the connector (most likely not the issue but a solid to look for and prevent issues)

The comment regarding installing a fuse is a big mess that was done incorrectly by Harley. The early 2000's Touring bikes had a circuit breaker that would trip so the first fix was a higher breaker, then a maxi fuse. The real problem is corrosion at the eyelet to the breaker that will get so hot it will burn you and thermally trip a breaker. Slapping the maxi-fuse in doesn't fix the real problem. The dead giveaway is a bike that goes COMPLETELY dead, meaning all power/lights and after a while of sitting everything comes back like it never happened.

I believe post 4 has the correct procedure for the 2000. It may be correct for 1999 but for some reason I seem to remember on a 1999 turning the ignition on-off-on-off and then on and leaving it on and it would flash codes. You are not starting the bike - it is done with the Run/Stop switch in Run and cycling the ignition switch. When turning it on you do it for a couple seconds. It's late, I'm old and it's the best I got.

 

So far I know very little about Harley’s, but what I know from other vehicles has me confused about this thread. The OP says his is Carbureted, but most of the other information makes me suspect it’s EFI. Check Engine Light Cam or Crank Sensors etc. Troubleshooting an EFI or Carb engine would be very different.

 

Digital timing control is one way to help a carbed bike pass emissions. It also works better in performance applications too. Nice thing about using a microprocessor to do timing is that it don't drift and it can tell you what's going wrong.