What is this hole for?

[Blacknsilvr]

In researching my no engine temp issue, I found this hole. What purpose does this serve? From what I can tell, it puts water straight off of the pump, into the same cavity that the poppet is when closed. Can anybody enlighten me on this?

[Dave S]

let the block drain so it don't freeze......

[Chaz]

It cools the bearing carrier in the lower unit ...

[Blacknsilvr]

It cools the bearing carrier in the lower unit ...

������ that’s a good one!

[Chaz]

Welp , it's true. The early 3.0L had two small holes , that when clogged up with sand and seashells would cut-off the flow of the only cool water the bearing carrier would see, and subsequently, burn up # 22 and # 26 allowing water to enter the case. Over the years. I have fixed a bunch of the early plates by installing "standpipes" in the adapter plate.
On later models, the factory fixed the problem by installing a tall strainer # 10 in the exhaust tube.
On tuners that I build from scratch, I use a tall, stainless air tool muffler

The 2.5 is a better design. Instead of putting the water port down in a "cup" that can collect junk that can /will clog up the hole, they put the hole in the flat floor where water running along the path can easily blow little rocks and shells thru the cooling system instead of giving them a place to collect.

If you don't believe me, plug the hole. Go surface your favorite wheel for a good long weekend ... and then tell me how much water is in your lower unit oil ...

[Blacknsilvr]

This hole I’m talking about, appears to “shoot” up towards the bottom of the powerhead. How would that direct back down, and land on the bearing carrier? I’m really curious, send me some pics of what you are talking about.

[flabum1017]

This hole I’m talking about, appears to “shoot” up towards the bottom of the powerhead. How would that direct back down, and land on the bearing carrier? I’m really curious, send me some pics of what you are talking about.

The water from the water pump comes up throught
the triangle cavity on the left......

[Chaz]

This hole I’m talking about, appears to “shoot” up towards the bottom of the powerhead. How would that direct back down, and land on the bearing carrier? I’m really curious, send me some pics of what you are talking about.

The best picture you will find is in the service manual for your particular engine. It will show in detail the different paths the water takes to deal with keeping your engine cool in all circumstances.
As far as the hole facing up onto the excess/ return cavity. I would say it serves two functions. #1 Many outboards have a flow diverter where the water has cooled the exhaust chest and now enters the heads. I know the 3.0L has a hole on the other side of the diverter that puts water from the bypass cavity ( cold ) directly to the exhaust port side of the bottom two holes. ( a bee-line to hottest spot first )
#2 To keep the base gasket cool ... OK .. maybe three # 3 To purge air out, before it finds it's way up to the closed thermostats ... and turns to steam ..
nUmBrrrrr 4 .. Dave ... It wUz 65* tOdaa, Wutz thiz frozen wAtur you speek uv ....
If you look in the top and bottom of your tuner / exhaust tube you will see the hole / holes that feed water DOWNWARD that cool the lower unit. They might not be in perfect alignment with the hole in the adapter plate .. but you will see there they share the same cavity ...

FlaBum ... I think you told me that you worked for Mitch at the Ft. Liquordale dealership. It was red beard Mike, the service mgr. at the Jensen Beach store that taught me about collecting seashells ... Wow, gotta be almost 25 years ago ...
Sumptin bout diggin a Bahamian trench ....

[Blacknsilvr]

Ahh, gotcha. I’m following now. I learned something today, thanks.

[Hupiveneilijä]

Hi!
Speaking of bearingcarrier cooling, made my own version.

[Chaz]

Ahh, gotcha. I’m following now. I learned something today, thanks.

We're all only as good as our teachers ... only dumb people I know, are the ones born knowing everything ...

Let us know what you find with your temp issue .... keep in mind, one of those red dot temp guns is your best friend when tracking down temp problems ...
A couple pieces of hose that fit the thermostat dumps will also let you see where the water is going.
Again ... on the 3.0L (they have issues) they idle @ Zero to five psi of water pressure. If the port side thermostat hangs open it will bleed off all the water, while the starboard bank ( which is physically higher ) will only fill to the height of the port thermostat and start making steam, that overheats the top cylinder, that sets off the alarm. The last logical thing you would do is give it some throttle to bring up water pressure. But thats the only thing that will fill that side to the top.
If the starboard side is stuck open ( temp sender, if only one, is usually on that side)
that side will pass all the water, and never show any heat on the gauge, while in reality the port side is burning up.

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Hupiveneilijä

Hi!
Speaking of bearingcarrier cooling, made my own version.

That's a smart move ...

Ignore the dumb joke I made to a friend about where to cut the water tube for a 15" mid ...

It might be a bit over-kill ... But I like to put the poppet bypass water thru the 3/4 inch tube on the right, directly on the carrier ...

[Blacknsilvr]

Will do. I think I have narrowed down to a poppet issue and idle rpm. We will see here pretty soon.

[Dave S]

Chazzz... I had a crabber that his 50 hp merc wouldn't shift..... It had periwinkels jambing the shift/ lock cam....

[Chaz]

Escargo ... ?

Kinda like the sand flea's we use to catch Permit on in the shallows down here ...

[FUJIMO]