2003 f25 has intermittent steam from tell tale

[rcaspari]

I have an intermittent problem with my f25.The motor runs perfectly and has plenty of water exiting the motor and is cooling unless I run it above 3/4 throttle for a mile or so then it will shut down and start sputtering and running with a miss. it still pumps water but it will steam when I throttle back down to idle,if I throttle up slightly water starts running and it will cool down after about 10 minutes. any help would be greatly appreciated.Thanks RICK.

 

[99yam40]

Re: 2003 f25 has intermittent steam from tell tale

how many years has it been since you replaced the water pump and thermostat?

 

[rcaspari]

Re: 2003 f25 has intermittent steam from tell tale

I rewplaced the water pump last summer but i have never replaced the thermostat.Where is the thermostat ?

 

[robaloroger]

Re: 2003 f25 has intermittent steam from tell tale

should be at the top of the motor with 2 screws holding it in place.You can testit by squeezing spring to slightly open then place fishing line in and let close. Place pot of warm water on stove. Turn the heat up and with a chicken thermometer (prefer digital) place in water and let thermo ahang in water. Do not let thermo touch bottom. When the thermo starts to open it will fall off the string. See what degree it open at. Not sure what yours should be but most thermos on larger motors open between 130-150 degrees. good luck http://www.**********/parts/search/Yamaha/Outboard/2003/F25ELRB/CYLINDER CRANKCASE 1/parts.html

 

[rcaspari]

Re: 2003 f25 has intermittent steam from tell tale

Thanks for the help.The problem was impeller fragments plugging the the thermostat inlet.I also tested the thermostat and it opened at 180-185. I took the boat out yesterday and had no problems even with surface temp of 95 degreesRICK