It depends how long the shaft stub is on the crankshaft. Usually a deep socket is better.

What makes these coils usually go bad is somehow voltage is sent through the "kill" wire to them. If you have a coil with no spark, and the kill wire disconnected, then the coil is bad. A good connection where the coil mounts is needed as well. If you have installed a new coil, and plugged up the "kill" wire and tried it, then disconnected the kill wire, then tried it, and still no spark, then your kill wire circuit must have voltage, and you have destroyed your new one. That is why there is a no return policy on electrical parts. Usually, the wires near the muffler, or the steering are in contact from damage, sending voltage that way. For the last poster, you have to disconnect the kill wire from the coil to confirm that the coil is fine, then follow the circuit through with an ohmmeter. Fish

What kind of engine drives the flywheel with a belt??? I've never seen that. If you removed the cylinder head, and you can see the valves moving, was the big, round thing (the piston) moving up and down??? Also, in most engines, the flywheel ( another big round thing) turns with the crank-shaft, when the shaft is rotated. This is because the piston is connected to the crank-shaft by the connecting rod. The flywheel is held on by a large nut, and has a key that keeps it in "time" with the crankshaft. The key is usually made of steel or aluminum, depends on the type of usage. good luck with yer quest! RJ

Had to use a gear puller to get the flywheel off - it came off just fine. The (plastic) gear on the flywheel had been chewed off - there was about 3" of mostly intact teeth on it - not enough to catch enough to spin it to start though. That was problem #1. Shopped around on Saturday looking for a ring gear. No one had one in stock. Found a local guy who had spare parts from other mowers & found a used flywheel with an aluminum ring gear on it. Cleaned it up & got ready to put onto my mower & noticed something wasn't right with the crankshaft. I hadn't noticed when I pulled the flywheel off that the centering tip on the gear puller I used had wedged itself into the top of the crankshaft. It would turn freely, but would NOT come out. After several hours yesterday of trying everything else, I was able to drill through it & eventually pop it out. Miraculously, the crankshaft threads were not ruined. After that, was able to install the flywheel with the aluminum ring gear. Also on Saturday, looking at the starter more closely, there was a "burr" on the threads of the plastic clutch, I suppose where it wasn't being released & staying engaged with the flywheel earlier. I was able to take the starter & spin it by hand and was able to make the gear stick at the top every time. I bought (another) clutch kit, this time with a metal gear & replaced it. Unlike before, this time I took steel wool to the starter shaft & shined it, then used lithium grease on it the inside of it. Put everything back together & then shot WD40 on the outside of the gear. With this, the gear returns each time, not sticking like the previous one (so far). Before my original post, I had tried to crank the mower. I turned on the fuel shut off & tried to crank it & eventually gave up. I turned the fuel off when I stopped, but wasn't able to empty what was in the carb since I couldn't get it to start. (Since I had problems earlier, I put the shut off valve in. Other than this time, I never turn the mower off - I cut the fuel off & let it run out of fuel). Once I got things back together, I tried to crank the mower. As soon as I turned the shut off valve to ON & tried to crank it (would not fire), I heard the glug-glug-glug-glug of the crankcase filling with fuel. Sure enough, oil level was about 1/2" higher than what I knew it was before trying to start it last week. I haven't rebuilt the carb, but replaced the float & needle when it had this issue the first time. This was the 3rd or 4th time this has happened. It happened the first time earlier this year when I was trying to fix it up for use after it having had sat for several years. I'm not 100% sure, but the fuel tank (gravity fed to carb) looked really empty before I put gas in it before trying to start last week. I added about 1/2 tank of gas. I use Sta-Bil in it & the stored gas which is about 3-4 weeks old now (I purposely ran it low the last time I used it). I wouldn't have run the tank dry, so I'm assuming the shut off didn't do it's thing. In reading about some of these engines (mine is a Briggs & Stratton 12.5 HP I/C Quiet, model 28m707-0178-01), I see numerous reports of the same issue. Even though I see that a complete rebuild appears to address the problem, I'm not sure how that is ever more than one failed start or not allowing the carb to run dry to reoccur. I'm sure that the ethanol is the culprit, but haven't yet found a source for "real" unleaded gasoline. Is there a reliable solution for using gas with ethanol? Also, given my most recent self-induced repair, I'm not sure I want to touch the carb.... ;-)