97 Yamaha 20hp 2 stroke leaking hot water

[DennisG01]

Thanks for that video - that helps a bunch and appears to point to the head cover gasket (possibly the head gasket, but less likely). A service manual (buy one - you really need it if you're doing your own wrenching) will have the proper sequence but generally you start in the middle and spiral your way out.

You can likely use your fingers and feel underneath the head/cover area to ID where the water is dripping from.

Does your engine have a high-temp alarm buzzer? I would "think" so, but I'm not sure. One would think that would sound well before the engine "hot seized".

It's best to put a new t-stat in.

[99yam40]

Thanks for that video - that helps a bunch and appears to point to the head cover gasket (possibly the head gasket, but less likely). A service manual (buy one - you really need it if you're doing your own wrenching) will have the proper sequence but generally you start in the middle and spiral your way out.

You can likely use your fingers and feel underneath the head/cover area to ID where the water is dripping from.

Does your engine have a high-temp alarm buzzer? I would "think" so, but I'm not sure. One would think that would sound well before the engine "hot seized".

It's best to put a new t-stat in.

agree, all water cooled motors need a working stat in place to make the water circulation flow properly .
even if you have to install the old stat with the center removed from it, to help with a little restriction.
some places will have too much flow with it missing completely and other with not enough flow, causing hot and cold areas

[panasonic]

Without being there and seeing with my own eyes exactly where it is leaking from and watching that video, I would say its the head gasket and/or cylinder head itself leaking on the bottom corner.
Could be just a head gasket or the cylinder head itself may have a hole corroded through or cracked in the water jacket.
For it to leak that much water I really don't think retourqeing the head would seal it up.

I dont have the manual for that engine so don't have the torque specs for the head.

This is a single carb engine...correct? Where are you located?