F90TLR ran out of water

[jackmanjls]

I was out fishing and a huge storm was rolling in down in FLA. The wind was blowing 50mph and the rain was coming down. I hastily put the boat on the lift and forgot to turn off the motor, it ran w/o water for about 5min. The alarm sounded after 3-4min and I immediately turned off.

After 10min I connected the motor flush out connector to the water hose and let the water circulate for 5min. The water was warm initially but cool at the end. The water pump was replaced 5hr back.

I then lowered the lift and started the motor and it seemed to be ok. The water pumped out of the pisser normally and the engine seemed to sound normal. I revved up to 2K and didn't notice any anomalies.

Am I out of the woods on this or is there anything additional I should do to further evaluate if there's any damage?

[Pas Bon F115]

I would change the impeller. Pull the foot off and you will see how hot it got at the water-pump might be okay, but I'd at least inspect it.

[jackmanjls]

PasBon what do you mean by pull the foot off, do you mean drop the lower unit?

[Pas Bon F115]

PasBon what do you mean by pull the foot off, do you mean drop the lower unit?

Yes, you need to drop the lower unit to inspect the waterpump. Not a hard job, look it up on YouTube...somebody has an example there to follow

[rodbolt17]

at a minimum you will need an impellor and a housing. minimum.

[99yam40]

If it runs and pumps well at idle with out alarming it is more than likely fine. Take it for a short run at high RPMs to make sure there is no overheat

Probably had enough water held in it to lubricate the pump after running on the water

[TownsendsFJR1300]

A rubber impellor spinning for 5 minutes against a SS cup will definitly cause some heat and friction without any water lubrication.

Besides dropping the lower unit and inspecting (I'd replace the impellor as well), I'd pay close attention to the plastic housing that holds that SS cup. If it got hot enough, it would have warped/damaged that cup..

A WP kit and two hours of labor is a whole bunch cheaper than potenetially a new motor, getting stranded, an overheat issue once, etc once away from the dock, IMO... Cheap insurance..

Just as a side note, I was PM'ed here by a member with plenty of water flow from the pisser but was still overheating. He later informed me that TWO "Fins"(wrong word) of the impellor had broken off (but still flowed water). One of the fins was blocking a water jacket.

[99yam40]

a motor started up dry is a little bit different than a motor that was running in the water with pump, tube, and head all full of water and then slowly lifted up and out of the water.
there is water to lube the impeller for some time draining back down the head and tube to the water pump due to gravity even with the pump trying to push air up it.

Yes I have seen pumps come apart when started dry

and I have seen impellers melted from clogged water pick ups when running
hard and no flow through the pump but they did not have good strong water flow out tell tail at idle. The exhaust running through the leg gets mighty hot the harder it is run, not so much at idle

Just saying it is on a lift and it is easier to take it for a short spin to make sure it does OK than to pull it out of the water on a trailer to get it to dry land to work on.
If it was on the dry it would be easier to inspect than to drop in the water for a run.

Any sign of problems then inspect right away or inspect next time on the hard even if no problems are found on the trial run

[rodbolt17]

how many chances at overheating do you get?
sometimes it only take ONE overheat.

myself I would take about 1.5 hours from my busy busy life, drop the case and inspect the housing for any signs of melt and the impellor sides and faces for any signs of melt.

but that's just me.

[99yam40]

well looks like I am overruled by a very knowledgeable Yamaha master tech.

Good recommendation.
Never hurts to make sure before causing something that could damage a motor

[Speedcop]

Water pump

Hi jackmanjls,
If I can just add my 2 cents worth, I had an old Yamaha 85 years ago.
My son ran the motor out of the water on the trailer. He thought it was a good idea to warm the motor before going onto the water!!!!! WTF?
It only ran for about 2 minutes, but...
I dropped the lower leg and dismantled the pump... The impeller was MELTED!
So I replaced the pump kit and all was well after that.
I would strongly suggest that you follow Rodbolts erudite and well-educated
advice and replace the pump kit. It's far cheaper than a new powerhead!
Regards,
Dennis.

[rodbolt17]

I did not say replace anything.
I did say I would tear it down and inspect it.
whole job takes about an hour.
1.5 if I am lazy.

[TownsendsFJR1300]

Depending on the Op's lift set up, he may very well be able to pull the LU right there.

I have extensions on my 4 post lift and an adapter to go in the space inbetween the extensions. I can pull the LU right on the lift (and in the shade) and have, several times... Trim the engine up, slip in the adapter to take up that space in the center and have at it..

With davits, just swing it in and check it right there..

[Speedcop]

Water Pump

I did not say replace anything.
I did say I would tear it down and inspect it.
whole job takes about an hour.
1.5 if I am lazy.

My apologies Rodbolt..., I just figured its better to play safe!
You are anything but lazy! Answering all those queries...! You are not lazy, just very knowledgeable on
just about anything to do with Yamahas, and then some!
Dennis.

[99yam40]

nice set up you have there

I really hate working on things in or over water

You know exactly where tools and fasteners will end up that get away from you