I have a 1987 FXR that runs great at idle, but when it reaches full operating temperature usually after a couple minutes of riding, starts running on one cylinder and then dies. When the bike sits and cools back down it will again start and idle just fine. So far I've changed the battery, the coil, rebuilt the carburetor, placed an inline fuel filter in the fuel line, and the wires and plugs were changed last year. This thing has got me baffled at how it'll run great until it gets warm, and then the problem arises.

Any help would be greatly appreciated.

 

Had a friend that the same thing was happening to, turned out to be the single-fire ignition module. Got hot, took a sh#t.

 

Do you mean the ignition module, or the ignition sensor/rotor? My bike still has the dual fire system. Thanks

 

Stock it has a dual fire module and a sensor plate. Either one could be bad. I just pull them both out and get a good aftermarket ignition. The Crane HI-4 with single fire coil is a nice unit. Or just get a aftermarket module and stay with dual fire.

Where it is heat related, I would think the module is most likely the problem.

 

My FXR has a screamin eagle module, DYNA S ignition sensor, and an accel super coil. Still Dual fire.

 

Found a bad connection on a wire going to the coil, put in new spark plugs. Runs great, but now it's running lean, have to rejet.

 

Hmmmm.Just found this thread,from one 87 FXR rider to another.Glad to hear your up & running.Good piece of info here,,,,,,,,,,thanks

 

We people with older FXRs have to help each other out. With the problems my bike has had the only advice my family has had is to get a different bike. I refuse, I'm very attached to the old lowrider. At least while my bike was down with the ignition problem I had time to change my rear belt, rear tire, and my inner clutch hub was kaput too. I'm getting to the point where I'm pretty knowledgeable on the FXRs. Keep ridin.