Just purchased a boat with a 2001 25hp yamaha 4-stroke on the back. The water coming out of the pisser is hot, I can put my hand under, but it is hotter than others I have felt. Then when I put it on the muffs it gets worse, can’t even keep my hand in it. Granted I think the muffs don’t make a perfect seal and it catches a little air every now and again. The motor pisses fine. Possible thermostat issue or am I a pus and can’t take the heat? How do you check for a broken thermostat? I am also running royal purple fuel cleaner through it. Would this cause it to run hot? No alarms have gone off (who knows if they work though). Thanks for any help!
Pull there thermostat out and drop it in a cup of microwaved water (very hot) if the thermostat pops open its good if not replace it. They are not that expensive either.
What does it do on the water? One problem with muffs is that even though water pump is picking up water - hence “pee”, it may not be picking up enough water to cool the engine properly - hence hot “pee”. Back it down in the water while still on the trailer and see what it does… or put it in a barrel to test.
If you ain’t retie’n, you aint try’n!
“it don’t pay to think too much on things you’ve left behind”- townes van zandt
I have a 2002 F25 and the stream on muffs isn’t that hot.
John
Pathfinder 23 HPS
quote:^^ This! I do this for every thermostat, even brand new ones. If it doesn't open that is a lot of money that it will cost you. Thermometer in a pot of water lets you know that it opens at the right temperature too.
Originally posted by reefraftPull there thermostat out and drop it in a cup of microwaved water (very hot) if the thermostat pops open its good if not replace it. They are not that expensive either.
Pulled the thermostat after some effort to get it free…thinking it was the thermostat now. Don’t think it has been changed for awhile. It was stuck open slightly and there was some substantial salt build up on what I think was the downstream side. Ran it with the thermo out, on the muffs, the water was WAY cooler. Thanks for the input everyone! Hopefully that was the issue and no damage was done to the motor.
O-yeah and thanks for the microwaved water tip reefraft…that is what I was going to do before I saw the shape of the thermostat!
quote:
Originally posted by reefraftPull there thermostat out and drop it in a cup of microwaved water (very hot) if the thermostat pops open its good if not replace it. They are not that expensive either.
no offense dude but very hot could be boiling 212* I sure hope it opens before that. Guess work is not needed.
130 degrees “feels” hot but won’t open a thermostat unless it’s designed to open at that temp. You can not go by guess work on a pot of “hot” water, but without knowing the temp of the water and what temp the thermostat is designed to open at you are basically peeing in the fan.