WATERWITCH MB-10 Magneto removal

[Bill Roth]

I am fairly new to the hobby, I’m now working on my 6th OB restoration. I have been stumped on this M-10 removing the aluminum mag drum and getting the nut off to remove the drum. Some one thought that the round nut, with 2 flats on the side, could be a left have nut(?) Its difficult holding the drum while wrenching on the nut. Please any suggestions on the nut removal and holding the drum! Bill, MN

[lloyd]

I assume that when you say “aluminum mag drum” you mean to say “flywheel”. If we are talking about the flywheel nut, it has 2 flats on it to tighten and loosen it and it is not a left hand nut. What you need to hold the flywheel while you loosen or tighten the nut is what is called a “strap wrench” which has an adjustable length strap that wraps around the flywheel and a handle to hold the strap tight while you wrench on the nut. They can be purchased or you can make your own using a 2 foot long piece of sturdy wood about 1 1/2″ square and a strap of sturdy leather or rubber that is about 10-12 inches longer than the outside diameter of the flywheel. Attach both ends of the strap near the end of the wooden handle with a couple screws through both ends of the strap into one side of the handle. Wrap the strap around the flywheel and fold the extra strap back on itself so the handle tightens the strap around the flywheel and can turn the flywheel. Flip the whole thing over to turn the flywheel the opposite direction. Now you can hold the flywheel steady while you tighten or loosen the flywheel nut!! I hope that explains it well enough. Sorry I can’t post a photo.
When the flywheel nut is loosened a couple turns, you can lift up on the flywheel while you tap on the nut with a hammer to pop the flywheel off of it’s tapered shaft. Good luck.

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