A little background on this 1978 C81. It hadn’t been cranked in 6.5 years and when I got it home, cleaned carb and put in a Lowe’s spark plug. A little fuel in cylinder and it fired right up. Happiest person in the world, until it shut off and wouldn’t crank. Checked coil, close to being bad, so it was replaced. Rebuilt carb, new point and cond. went through hrs of retiming and setting point, still wouldn’t crank. Checked fire to plug and had spark. Bottom line was, bad new plug. Finally figured it out by taking plug from electro 12 and there you have it. I’m just a rookie on the small engines, but with all the help here, figured it out. My last extra spark problem was Grounding. Removed points and sanded points base and base on block, no extra spark. What a wonderful site to soothe from blowing up a good tractor. Now, I will refurbish this one first and the tackle the electro 12 next. The 12 is a running tractor but needs some love. The C81 still smokes some, but I can live with that. You guys are great. Patience, I’m starting to learn since retirement.