250 4 Stroke 2007 Flushing

[Capt.Terry]

This is my new outboard used but in great shape. just need to know on trailer if I can start it with a hose attached to the upper flush and a hose using earmuffs on the lower unit at the same time... the engine is cold, and will it pee when it warms up. I am concerned doing this as it is a big outboard and don't wish to screw anything up. I have done engine off with the hose flush and no pee.? after reading. It may not pee because it is a big head. and just using the muffs alone I am concerned that the water may not be enough for this size engine. Good pressure on water. also if this has a high speed water intake should that be covered for better muff results. Not sure if the upper hose flush is feeding the water in the correct direction as it may be a back flush of the head ? just need to know if anyone owning this outboard and HP 250 4 stroke is doing this with great results. Hopefully a Yammy representative can advise Thank you

[rodbolt17]

use a set of muffs on the lower and the onboard flush and your ****en.

NEVER use muffs alone.

if you only have a single hose run it on the onboard flush but for no more than 5 min.

the two lower unit pickups are separated at the pump.
unless a monkey did the pump last.

[TownsendsFJR1300]

G0lden!!

Why that word is restricted,

[Capt.Terry]

use a set of muffs on the lower and the onboard flush and your ****en.

NEVER use muffs alone.

if you only have a single hose run it on the onboard flush but for no more than 5 min.

the two lower unit pickups are separated at the pump.
unless a monkey did the pump last.

Thank you for the reply..
The outboard is so costly to make an easy mistake here. I have the concern if the water volume from the muffs isn't actually getting there to and thru the head, as it flows out so freely from the lower unit, damage would occur fast.
I was thinking the or a thermostat would be holding back flow until it opened like in a car, and this momentary high heat would be not good . But this may not be true! I am thinking of taking a "Y" adapter to the hose and using the muffs and the engine flush connection together to get the water up an in ? The muffs keeping the water pump cool and wet and sending water also. Just not sure about if the pump is sending up the water to come out the head flush connection at the same time and it would just pour out uselessly. and Why does Yamaha say not to run engine with the flush out ? now if they continued on to say it because would lead to a fast failure of the water pump impeller to over heat and burn up I would understand. But is there more to it ?

[boscoe99]

This is my new outboard used but in great shape. just need to know on trailer if I can start it with a hose attached to the upper flush and a hose using earmuffs on the lower unit at the same time... the engine is cold, and will it pee when it warms up. I am concerned doing this as it is a big outboard and don't wish to screw anything up. I have done engine off with the hose flush and no pee.? after reading. It may not pee because it is a big head. and just using the muffs alone I am concerned that the water may not be enough for this size engine. Good pressure on water. also if this has a high speed water intake should that be covered for better muff results. Not sure if the upper hose flush is feeding the water in the correct direction as it may be a back flush of the head ? just need to know if anyone owning this outboard and HP 250 4 stroke is doing this with great results. Hopefully a Yammy representative can advise Thank you

Your engine should pee whether it is hot or cold when the boat is in the water.

Your motor may very well pee just fine using flush muffs alone. Some however won't. Depends upon the volume of water that is being provided to the lower unit inlets. Your motor has dual pairs of water inlets which can (not will) make it a bit more fiddly to get water into the lower unit via flush muffs.

If your motor is one of those that does not do well using just the lower unit flush muffs then what has proved to work about 100% of the time is to provide water to both the lower unit and the garden hose flush fitting at the same time. Again, it is important to have plenty of volume. This takes lots of water pressure and a large size hose that is not any longer than it needs to be. Using a tap that has about 30 psi with a half inch diameter hose that is 150 feet long might not get the job done.

With water being provided to the motor via both inlets (lower unit and garden hose fitting) I would expect that your motor will start to pee before you ever crank it up. Give it about a minute and see what happens.

[pstephens46]

I use two hoses and my F150 pees in about 5 secs after starting. With just muffs it was difficult to get it to pee at all. Never overheated. Max running time maybe 20 mins.

[rodbolt17]

NOTE
I mentioned TWO that is 2 hoses not a hose with a Y.