2048 Webb Street, Stockton, California 95205
After working on and rebuilding five gas engines, I never was faced with the problem of removing the flywheels from the crankshaft of any of the engines. Then my luck ran out. I bought a very old engine in Montana, that had been stored in a dry barn for at least 50 years. When I looked at the engine, it seemed to be stuck, but there was a slight movement, which led me to think it was old oil and grease, not rust. So, I bought it, and when I got it back to California and took it apart, I found the left hand wheel had a nasty wobble caused by a bent crankshaft. A friend who worked for a tractor company said he could straighten the crank if I could get the flywheels off. The gib key on the pulley side came out easily, but the key on the bent side was smashed and beat till there was nothing to get hold of. Then I thought of an article I had read in GEM several years ago. A fellow had written about drilling gib keys out. I couldn't find the article in any of my old copies so, I thought, if this fellow did it, then that must be the way to go.
The first thing I did was take a small flat file and clean off the nicks and sharp dings on the key way. The key way was 5/l6'so I took a 5/l6' transfer punch putting it in the key way, up against the smashed key and gave it a hard hit, making a nice mark for the drill to start on.
Then I bought a 5/l6' by 12' drill bit. I placed a 4x4 under the left side so the crankshaft was at a 45 degree angle, making it easier to drill on. After filling the key way with grease, I put the drill in, and clamped it down with a stainless steel auto water hose clamp, tightening it down so the drill was held firm, but could still be turned freely. This way the drill bit could not jump or wander around, only go forward or back. Then hooking my hard drill on, with my son bracing the motor, I started to drill. The drill centered on the punch mark and started to cut in. I drilled about a ?' at a time and then backed it out and my boy would give it a shot of oil. In a very short time the bit came through on the inside. The key was pretty tough steel but not hard. After removing the drill, my son held the flywheel on his side and I gave the one on my side a twist, and it turned freely on the shaft. The gib key had been drilled out and was just a shell. There was no damage to the crankshaft key way, or to the flywheel key way. After the crank was straightened and I fit in a new key, the wheel was 90 percent better, but still had a little wobble. But when I'm 85 years old, my wheels will wobble, too.
Thanks to the fellow who wrote the first article and gave me the nerve to try it myself.