Dry Firing Outboard

[DogDaysDestin]

I have a Yamaha 150 and there’s been two times where my dad has dry fired my motor out of the water, I stopped it within 3 seconds both times but I’m curious if this could have caused any problems?

 

[roscoe]

Yes. Easily could have damaged the water pump impeller

Time to replace it.

 

[DogDaysDestin]

Yes. Easily could have damaged the water pump impeller

Time to replace it.

Damn, just got a new one put on 3 months ago. Any way to know if it’s shot without taking off the lower unit?

 

[stresspoint]

I have a Yamaha 150 and there’s been two times where my dad has dry fired my motor out of the water, I stopped it within 3 seconds both times but I’m curious if this could have caused any problems?

in short , no , that is if the motor has recently been in the water or running with water on the muffs.

on a dry motor , yes , it will chew the water pump impeller in no time, the water lubes the impeller and they cook real quick when dry.

 

[racerone]

The concept will not change.-----Every day there are new boat owners who need to be taught.----Running a boat / motor is not the same as jumping in a car and pushing a button.-----Do not run an outboard dry !!!

 

[flashback]

3 seconds at 700 rpm and you may be okay, 3 seconds at 3000 rpm and your probably not okay..

 

[jimmbo]

I guess the only way some will learn not to dry run the Engine, is having to buy a new Powerhead.... No Sympathy for them

 

[saltchuckmatt]

I have a place with buoys to moor the boat....the neighbors kids dry fire the engine quite a bit and then lower the engine. They seem to be fine.

Like was stated at low rpm? Probably fine.

Other factors apply like age of the impeller.

 

[jimmbo]

Do what you Want, it is your engine, and pocketbook.
When the engine is tilted up, the is still a bit of water left in the housing, and in the water tube, these do take a bit of time to drain. If the engine was never lowered when out of the water or shaken too much, there still might be traces of Water in the pump, but I am not willing to bet the Power Head on it

 

[airshot]

That impellor is a very tight fit inside the housing, the rubber fins are under great strain in order to pump water quickly and in volume. There is so much friction when dry ( out of the water) that the rubber impellor can overheat and become damaged in seconds. Next time you have it in the water, watch closely, you should see water from the telltale almost instantly after engine starts. If there is a hesitation of more than a second or two before seeing water....time to replace that water pump!! Muffs wont tell you anything as the pressure from the hose will make the water flow.

 

[jimmbo]

It takes some time to fill the Block on the Inline sixes before water came out of the Teltale, about 6 or 7 seconds. Some outboards had the Teletale located before the water got to the Block, so there it would be faster.

 

[airshot]

It takes some time to fill the Block on the Inline sixes before water came out of the Teltale, about 6 or 7 seconds. Some outboards had the Teletale located before the water got to the Block, so there it would be faster.

Didn't think of that, but looking back my inline 4 cylinder does take longer than my older twin cylinder motors....

 

[stresspoint]

Didn't think of that, but looking back my inline 4 cylinder does take longer than my older twin cylinder motors....

some motors have different poppet valves, thermostats and water flow , for example , my 4 stroke Yamaha takes 10 seconds or more to start pissing water with a new pump .
you should be going by the strength of the flow once water flows rather than how long it takes to initially start to pee..

 

[harmanoff]

i replaced my impellar last year, first time ever doing so, was super simple!

 

[airshot]

some motors have different poppet valves, thermostats and water flow , for example , my 4 stroke Yamaha takes 10 seconds or more to start pissing water with a new pump .
you should be going by the strength of the flow once water flows rather than how long it takes to initially start to pee..

Yes, when mine does start, it pisses like a race horse !!

 

[Bman1337]

For years now Ive fired my 70 Johnson up countless times out of water. sometimes after it just come out the water so not true dry fires, but alot of times just in the yard because i like to brag about having an old Johnson that starts like its fuel injected haha, And i havent repalced the pump since buying it and it still pumps a good stream at the lake every-time with no signs of failure. so i personally don't think dry fires for a couple seconds at a time actually cause any damage. However i think it CAN happen under the right circumstances. I believe in most of those situations where someone says they dry fired it once or twice and killed the pump that pump was probably already on the verge of failure.

Though i 100% agree about just going ahead and doing another pump change anyway. its not that pricey and its cheap insurance.

 

[jimmbo]

Think what you want, and when it fails out on the water, you can think about it some more, as you row back

 

[Bman1337]

Think what you want, and when it fails out on the water, you can think about it some more, as you row back

Thats why i said i think and not i know haha. ive been meaning to check its condition one of these days. i have seen some pretty ugly pumps come apart that did somehow still pump water.