40 hp yamaha overheating

[lonnie1975]

I have a 40 hp yamaha that was overheating, light would come on, but the pisser still had water coming out(not very hard).I took down lower unit and change water pump imp. but still the same.I then took out the thermostat and the overheating went away. My question is how necessary is the thermostat and should I replace it or can I leave it out? Thanks inadvance.Lonnie

 

[andy6374]

Re: 40 hp yamaha overheating

Very necessary.<br /><br />Seems like it was stuck closed. Replace and test again. I bet you are good to go.