I’ve got an 18R engine, it runs just fine (when it does). I keep it up with oil/filter, points condenser all the standard stuff. So now the problem I can sometimes start it and it would run for awhile then just stops. I’ve replaced the following parts—the ignition switch, coil, resistor that sits on top of it, the starter just because of so many no starts, fuel filter, fuel pump I took the line from the carburetor off and it pumped fuel just fine, and a new Weber carburetor. When it starts it runs great a solid 900 RPM. The run time (when it does) is about 30 secs to approx 2 to 3 minutes. When it dies it just drops no studder no extra rolls. You look at the tachometer the needle just drops. This model has a starter cancelation switch on it. If I were to push the button on it the relay inside would click like it always has done. I am so done playing the parts replacer. I just now stand and just look at her thinking what the hecks goin on? I’ve had this thing since High School never had this happen before. The ironic thing is that I was just gonna run down to have it restored at my restoration shop…go figure. Any thoughts?