Thanks for all the feedback. To snubber - My local Tohatsu technician with 30+ years of experience has no idea what happened to the engine but feels it is probably not cost-effective to tear it down. The engine has been well taken care of, serviced regularly, and was running last season. When I went to start it this season, after wintering in the garage, it was frozen. He did the usual stuff, removing the cartridge, checked the oil, and loosening the bottom section to see if he could get the driveshaft to budge - nothing. It seems it is something in the powerhead - not gears. He has never seen a Tohatsu freeze up like this. I'm going to get a second opinion and then keep it as a project, but I'm not counting on getting it going. Whats stage is that it would freeze completely after sitting, without a catastrophic event.