f225 txrd getting hot.

[Keith Ohanesian]

Ok guys. At idle its at 150 then after about 15 mins at 4200 rpm it starts to climb. Sits at 185 running 45 degree water. If I open it up it will go to 190 with no alarm. The engine has 1400 hours with a new impeller. I scoped the exhaust and it looks ok with minimal corrosion. I have no idea if the stats have been changed of the relief valve. All info came off of my mfd. All is to be changed as soon as the parts arrive.

My question is if the prv is stuck or clogged would that create the high temp? I know the impeller was changed with the kit and they reused the housing.

[panasonic]

Have you looked at the thermostats?

[Keith Ohanesian]

No I have not. I'm pulling them in the morning.

[pstephens46]

Why do you think 190 is high at a higher rpm? Fairdeal will weigh in with his observations. No alarm, right? I can’t recall the trigger point on the F225. Five minutes of WOT on my F150 will result in a temp of maybe 225. Alarm is supposed to sound around 258?

what is a mfd?

[Keith Ohanesian]

Multi function display.

I believe the stats are 155. If that is true 190 is way above them. Especially in 45 degree water

[TownsendsFJR1300]

How long have you had the boat, is it "new" to you? (Trying to get to "service records")

What year engine and is it used in salt water?

If so, flushed regularly?

[fairdeal]

Boscoe has often commented on the trouble that can be caused by being given additional "data"

the "mfd" is displaying the "engine temperature" - a sensor set into the block

so not the temperature of water passing through the cooling jacket but rather, the mass of metal itself

yes, the thermostat is rated to be fully open by 155 F

but the Yamaha-defined "overheat" point of that "engine temperature" is 248 F

I find on my F225txrd that the "engine temp" runs ~180 with a light load (just me) and rpms between idle - ~4000


but put a few hundred lbs of passengers aboard, and crank up closer to 5000

and the temp will creep up

I have seen it as high as 205

but obviously, since there is no "alarm" at that time

that means the water passing the thermostat - where the thermoswitches are -

is still less than 194

[fairdeal]

[99yam40]

My question is if the prv is stuck or clogged would that create the high temp?

It dumps excess water pressure, so if stuck open it could over heat at low RPMs (idling)
Higher RPMs it should be open anyway

[Keith Ohanesian]

Thanks fairdeal. I am a firm believer off to much data can be trouble also. I have bad luck with engines lately and don't know much about this new to me engine. I forgot to mention when I stopped that I felt the water out of the pee hole and it was cold.

[99yam40]

tell tale water does not run thru the motor on Yamahas so it never gets hot.
It does cool some fuel on some motors tho

[Keith Ohanesian]

tell tale water does not run thru the motor on Yamahas so it never gets hot.
It does cool some fuel on some motors tho

Thank you for the knowledge. Where does the water go? Is there a water flow chart for this engine?

[panasonic]

Here is your engine manual, if you don't already have it....

https://www.vansoutboardparts.com/se...0&limitstart=0

[boscoe99]

Thank you for the knowledge. Where does the water go? Is there a water flow chart for this engine?