Are you sure its a Tecumseh? Ive seen Kawasaki’s with diodes in the harness but not any Tecumseh’s. Either way I would check the coil gaps first.
where are you getting the coil? My unit has coils from a engine that had been running fine until the guy seized it from poor oil maintenance.Did that. Spark looks weak on driver side (front left viewed from the seat) cylinder. That is with both kill wires disconnected from the coils. I have ordered a replacement coil ($36). Will update this post once it arrives and I test that. Many thanks for all your help!!
UpdateI was just working on mine again. Left cylinder as I face the heads is definitely messed up. It was ok when I fixed carb on right side. Had hi on temp gauge on exhaust before my test cut run. I removed the kill wires from the coils and it was still bad. I added my own wires for testing. I could kill left side and right ran fine. Adding back left it ran bad and killing right only the engine stopped. I swapped the coils side to side but nothing changed. I did locate the diode in kill. The right wire comes across into a heat sleeve. The left one also goes into that heat sleeve. I found the diode just inside the top of the sleeve for the right lead. Since only one lead comes out the other end of the sleeve I assume they are spliced in the sleeve. I will have to pull sleeve off to see diode in the left lead. For now I have the left carb including the bowl in the ultrasonic cleaner.