So last fall I bought a 912uls "for parts". Had to drive up to Minnesota to get it. The old engine was in the crate that the new engine came in. The were a few pieces that came with the new one including a new oil tank. It was sitting beside the plane, a Searay.

The story was that the engine got to where it wouldn't start. They said the word from the local Rotax shop was that the too heavy prop had damaged the gearbox to the point that the small gear in the gearbox had spun on the crankshaft. The partners in the plane had elected to buy a new engine and put on a lighter weight prop. I bought the crate as a box of parts. Maybe I could make something of it else sell the parts.

At the time I talked to Hal Stockman and just said I had a motor with a bad crank and what would it take to fix. We talked a few options.

Well today I called again and described it in more detail. He said to take it apart myself and look to see how bad it was. So this afternoon I blew off work and got the rear housing off. That was easy sense the shop had been in there and everything was loose. The sprag clutch is gone so I'm guessing it was bad. The mating surface on the gear looks just fine.

Got the magnetic plug off. Hard to do, really had to work to get it off, old style. Shop sure hadn't touched it. Not too much stuff on it, maybe 1.5 mm. Then I got the gearbox off. Hard to do. All the screws were tight and I'm sure I was loosening Loctite. Had to really hammer with the slide puller to get the gearbox off. I think the sealant was fresh. Then the big finish: took off the big nut and small gear. The spines in the gear and on the crankshaft are perfect.

It doesn't look like the gearbox was taken off at all. The only thing wrong was probably the gearbox dogs and the sprag clutch. I'm going to replace the gears and inner dogs in the gearbox. Plus the sprag clutch. Looks like ~$2500 for everything.

Hard to say what the deal was with that shop. Miscommunication? The logbook shows a little over 1200 hours and the engine worth much more than I paid for it.

So next purchase is a motor mount from Kitfox.