@Chuck Sartor posted:
If the chuffing was working before you took the smoke lever out and now it's not, I wouldn't think it would be the board. Check for a loose plug on the circuit board, loose plug for the sensor and on/off switch. Possible pinched wire at the sensors, Is the blade paddle dropping down to cover the sensor and then clearing them? Defective on/off switch. Usually when the boards go bad, nothing works.
I see what you are saying Chuck but after reassembling the engine I still had intermittent chuffing at least for a while . I got disgusted so I turned the chuff switch to off and noticed that for several revolutions around the layout I continued to get the intermittent chuffing. Then it stopped. Then I turned the chuff switch back on and now I get no chuffing. So , I had some intermittent chuffing after I fiddled around with the smoke lever. I guess its possible something loosened up in the process and took a while to work its way completely loose. I checked for the things you suggested when I had the hood off and found nothing amiss at least as far as my unpracticed eye could discern. I will, however, go back and follow your suggestions and see if I stumble on anything. Can't hurt. Frustrating. Oh, also the blade seems to covering and clearing the sensors as it should; again at least as far as I can tell.