1997 Ski Nautique 196 engine running cold.

I think it was stuck open and when you took it apart it closed back up. I doubt you celebrate this weekend like we do but if you want to save the weekend it might be worth a try to reuse it while you wait for a new one. Unless you can get one up there easy. Just keep an eye on the temp gauge. I had one stick closed this season on it's first run but after shutting it down and restarting it never happened again. It's on my list to change though.

I have the same conversion running in salt and have not had problems yet,knock on wood,I doubt you running in fresh,if you are,would. Very hard to see and measure but the hole seems to be 3/4" wide by 1/2" high. This is the lower thermostat housing it feeds the water into the circulation pump then into the block. The thermostat keeps the water in the block,as the water warms up the 'stat opens allowing cool lake water to enter into the system thru the hole



This is the upper. The hole is approx 1/2" This is where the fresh water comes into the engine it bypasses all the time into the exhausts to keep the manifolds and exhaust hoses cool. As the thermostat opens the hot block water also exits into the exhaust manifolds. Your thermostat,if stuck open will just bypass all the water never keeping it in the block long enough to heat up



These parts are no longer available new,used is your only option

Stuck open thermostat. When you took it apart most likely closed. Best just to replace it. Hole is a bypass and is supposed to be there