How much water pressure for flushing

[troy]

What is the safe amount of water pressure for flushing your motor.
In my back yard i have a inch hose with plenty of pressure but in the front yard i only have half inch with little pressure.
Is it safe to flush on the smaller hose as when i pull my boat out the inch hose will not reach and it makes it hard to flush with the targa down.
Thanks
Troy

[Kerry]

Safe amount is to stick it in a drum with enough depth of water and let it pump itself, a hose can not supply the amount of water an outboard can pump.

A drum in many cases is not practical but if you have to flush on hose and many have to do this then

- nothing above idle
- not for an extended period of time
- ban water use by everybody else, no shower, no toilet flush, nothing!

[Deiter]

Kerry, is it alright if i say that i am not completely convinced of what you say here?
Maybe you don't have very good water pressure up in the bay area, but there is no way my 90hp sucks more than i can feed it while flushing.

Now, i know that the amount of water drawn into the cooling system by the impellor is directly proprtional to rpm, and i only take mine above idle if it needs a bit of throttle to start, so don't you think it is a bit of a gross generalisation to insinuate that nobody's tap pressure thru a 1/2" garden hose is suffice to supply cooling water to any outboard, if this is indeed what you are saying?
Maybe in Troy's case, if water pressure is low. But.

Does anyone actually know the rate of water usage of an outboard at idle with zero pressure up its date (i.e.sitting in a drum), as opposed to being force-fed with a hose and muffs?

Damo

[Kerry]

Deiter, A good mechanic can tell you if an outboard has been running on mufs or not without even knowing simply by looking at the impellor but more so from the casing/housing.

And yes I am saying there is not enough water "volume" through a 1/2" garden hose to satisfy most motors and especially in Troy's case and I would guess even with a 90?

Regards, Kerry.

[OPTI]

troy,the 1/2 inch should be fine.the last 2 engines i had were 225 s and thats all i have every used.by the way im a qualified out board mechanic ,22 years,i run most of my customers engines on the flush,never had a problem,even at high revs.
you need to be carefull with the drum option,it would need to be quite big in diameter,its easy to suck your exhaust gass into your water intake,which i have done .tanks are what most shops have that arnt near the water.
it will probably suck all the hose can give it,but if your muffs fit tight you wont have trouble.
regards opti;D

[Chimo]

Hi All

While on the topic what are the negatives of or benefits of just plugging the hose into the motor; in mine ; in place of the tell tale outlet, instead of muffs.

I believe you dont run your motor in this case, just flush with tap water.

Does the thermostat etc get properly flushed withthe hose on the tell tale or not?

So what are the pros and cons of both methods?

What gives the best outcome for the motor?

Thanks in anticipation

Cheers
Chimo

[tully]

troy, I would imagine that as long as you have water coming from your telltale in a reasonable stream you have nothing to worry about.