F150 costly mistake

[Nautical]

The picture shows the water level is clearly over the suction intake and the pee stream shows that the impeller is moving water through the motor so it was getting lubricated as it pumped the water from the bag. All looks Ok from the picture.. The impeller as stated above was probably melted due to lack of water or dry running.???During the storage period someone may have run the engine w/o water to it.. Just a guess ??

[rodbolt17]

if you trim it high enough to uncover the water intakes???? yep melted impeller/housing and most likely an overtemp alarm.

why not simply use the provided flush port????

this cwap aint that complex.

until you make it complex.

[99yam40]

this kind of thing is a good reason to inspect/replace the water pump often as Yamaha lists. making sure impeller is good and greasing up shafts and bolts.
Well worth the time and effort in the long run

My brother has a little 25 jonnyrude that some of the lower unit bolts will not break loose on.
It still pumps OK so he does not want to break things to get it apart just yet

[boscoe99]

Thanks, for all the posts. Yep I &^%$up, still scratching my head why alarm did not sound with this kind of damage. Certainly concerned if there was a possibility this could happen trimmed in shallow water ?? Like most of us we all have (or at least some of us middle class back yard mechanics) attempted to do most simple procedures as flushing which have been the norm for previous owned engines. The barrel set-up mentioned is what local dealer currently used, with housing submerged. Further comments appreciated

The alarm will sound if and when the thermoswitch, high up in the motor in the top of the cylinder head, closes due to over temperature. However, the impeller is down low where there is no thermoswitch. Running an impeller dry can ruin it long before the cylinder head gets hot enough to close the thermoswitch.

Just never run the impeller dry and the chance of damaging an impeller is nil. Either submerge the lower unit to the point that the impeller is under water*, use flush muffs with enough pressure to force water up to the impeller, or use the garden hose flush fitting and let the water run long enough to fill the block and then work its way down to the pump.

*Don't count on a dry impeller being able to suck water up to itself. Pumps work so much better pushing fluids than they do sucking fluids. There is no limit to what a pump can push. There is a finite limit to how much it can suck, if any.

[boscoe99]

this kind of thing is a good reason to inspect/replace the water pump often as Yamaha lists. making sure impeller is good and greasing up shafts and bolts.
Well worth the time and effort in the long run

My brother has a little 25 jonnyrude that some of the lower unit bolts will not break loose on.
It still pumps OK so he does not want to break things to get it apart just yet

Brothers are like that. Unfortunately, I have two and are one.

[almetelo]

Have a look on the link

Boater's Log Vol. 5, No. 2 | Yamaha Outboards

The LU on 1st pic is completely submergedn and yours isn´t...

[theflats]

if you trim it high enough to uncover the water intakes???? yep melted impeller/housing and most likely an overtemp alarm.

why not simply use the provided flush port????

this cwap aint that complex.

until you make it complex.

rodbolt, trim height never high enough to expose grates. during the end of season winter prep (pictured), running a freshly topped fuel tank with Stabil 360 (aluminum tank) to enter the fuel system. are you stating use flush port to run engine ? (correct me please as Yamaha does not recommend running engine on flush hose).
Appreciate your knowledge and expertise and member recommendations.

[Nautical]

I believe you can run the engine for short duration and at idle speed on the flush out hose attachment. The book may so no to avoid people abusing the term short duration and /idle speed. Like Boscoe above says its vital that the water is saturating the impeller housing and is pouring out the peehole. That's my experience, but best to follow the book.

[boscoe99]

Funny how people want to "follow the book" but only when it meets their agenda.

Yam says no reason to run the motor if using the flush fitting. Just use the fitting without starting the motor. Folks don't want to accept and follow that concept. They think the motor has to be run.

Yam says to not run the motor if and when using the flush fitting. Folks think that is the gospel.

So, they don't believe part of the book but think the other part has to be obeyed.

The book is written to the lowest common denominator. Yam has no idea what types of folks buy their motors. They are trying to protect the most dumb of all of the Yam users.

[rodbolt17]

just yesterday I finnesd a block install on an F250.

I started it on the flush port on the engine.

I do it daily.

[throrope]

This is IMHO a lesson only learned the $ way. As rodbolt can witness, you only get that parental watchful eye after parting with the $.