I have stripped the engine. When I looked inside the gearcase, so I opened that, and yes - the gears were covered in rust. I have removed the propeller shaft and propeller gear, and the gear is pitted. Is this gear useless for all purposes - should I check it?
In other news, I'm trying to take off the driveshaft, but the pinion gear won't come off - it may be rusted on, but I can see what looks almost like a broken cotter pin in a hole in the pinion gear. Is there a trick to getting these pinion gears off?