00 150 ox66 saltwater series 2 alarm question

[quackills05]

had solid alarm come on other day on lake..got boat to house cranked motor no alarm for 15 min...recently changed water pump and impeller and all oil filters fuel filters....i noticed the water coming out the pee hole never got warm..question is could that be thermostat...also how do i change thermostat and the prv

[boats.net]

It could be overheat alarm or low oil alarm, check level of oil in engine oil tank if below bottom line on tank then it's not transferring oil from boat tank to engine tank.
If engine is overheating then could be water pump, thermostats, or pressure control valve.
If you have Yamaha gauges with warning lights it will show which alarm is activated.

[quackills05]

well the water pump isnt 6 months old and was working just fine...the oil level is good as i check it regularly and it was pumping fine as i checked it out..how do i go about the thermostats and pressure control valve?? thanks

[tom976]

Thermostats are on top of each cylinder head and the pressure control valve is located on the back by the computer (on the bottom)

Its about 3/4" wide, has two bolts on it and has a hose going to the starboard side of the motor.

[quackills05]

thanks

thanks a bunch

[videorov]

Had the alarm go off on one of mine and it was fuel pump

I had just put on new water pumps so I thought it couldn't be that.
If I ran faster the alarm wouldn't come on. But if I drove along slow
it would come on. Took it to the shop and to my surprise it was a bad
fuel pump setting the alarm off.