How to fresh water flush on Mercury 9.9

davidpm · #1 (**permalink**) 10-24-2011

I did not see any obvious place for the water pickup.
Then I got the bright idea, I hope, that if I picked the engine up after running it and checked quickly I would see where the water ran out which might be the same place as the intake.

So I got to take a couple pictures, not the best standing on my head over the back of the boat.
The first one shows the stream coming from jut below the cavitation plate.
The second one is over exposed but shows the hole just above a bump.

How does one hook a hose up to such a difficult place. I don't see how standard muffs will work?

Faster · #2 (**permalink**) 10-24-2011

I helped with the coach boat for my wife's Dragon Boat team, they had newish Merc 9.9s that had an external circuit that you could disconnect and hook a regular garden hose up to it for flushing. The connector was just beside/outside the cowling, up front opposite the tiller arm.

Worked slick but I don't know if it's standard nowadays or if it was an add-on.

What year is this motor???

davidpm · #3 (**permalink**) 10-24-2011

Don't know the age but it is 2 stroke so have to pretty old I suspect.
Runs great so far.

3Kioni · #4 (**permalink**) 10-25-2011

The 2 stroke small HP Mercury outboards pick cooling water up through an opening underneath the anti-ventilation plate (sometimes incorrectly called the cavitation plate) just forward of the anode. There is a hose adapter, which has a single "muffler" and spring plate arrangement to hold the muffler over the cooling water inlet. The prop has to be removed to give clearance for the adapter.

jjablonowski · #5 (**permalink**) 10-25-2011

I remember seeing an article in a sailing magazine years ago that described how one owner rigged a floatation collar around a lidded bucket, filled it with fresh water, and tied the floating pool to his saltwater mooring.

Before leaving the boat, he'd pull the bucket up to his stern, lower the outboard motor into it to run a couple of seconds in fresh water, then hoist the motor.

davidpm · #6 (**permalink**) 10-25-2011

Quote:

Originally Posted by 3Kioni

The 2 stroke small HP Mercury outboards pick cooling water up through an opening underneath the anti-ventilation plate (sometimes incorrectly called the cavitation plate) just forward of the anode. There is a hose adapter, which has a single "muffler" and spring plate arrangement to hold the muffler over the cooling water inlet. The prop has to be removed to give clearance for the adapter.

That sounds like what I have.

I'll see if I can find a link to one on-line. If anyone happens to run across it please post it.

It will be a pain to remove the prop while it is in the water.
Maybe the bucket or bag idea will be easier.