1975 225 OMC

[Rranger]

When I have my outdrive in a tank and start it up I get a stream of water spraying down behind the piece behind the piece of hose in the picture, does that mean my water pump in the drive is pumping water? I’m told that’s what that spray means. Because I’m not getting water through the intermediate hose to the thermostat housing.
Cools fine and water flows to thermostat housing off the hose.

 

[Scott Danforth]

there should be a cap on that fitting. that fitting is a flush fitting to flush the motor when out of water and should be capped.

running without the cap will mean your pump is just pushing water out the connection and not thru the motor

 

[Rranger]

I have the cap on that was a before picture. The stream comes from behind the four bolt piece behind the hose fitting. Is there a tell stream of water on the omc 225 like a outboard to confirm the water pump/impeller is working?

 

[kenny nunez]

The stream is so you know the water pump in the drive is working. With the boat in the water the stream should put a dent in your finger. Also with the boat in the water the hose to the thermostat housing should put out enough pressure just above idle that you cannot hold it back with your hand on the end of the hose.

 

[Rranger]

The stream is so you know the water pump in the drive is working. With the boat in the water the stream should put a dent in your finger. Also with the boat in the water the hose to the thermostat housing should put out enough pressure just above idle that you cannot hold it back with your hand on the end of the hose.

Can you think of a reason I have the stream but no water getting to my thermostat housing? I did unhook the hose at the thermostat housing, then hooked a garden hose to that end and forced water backwards and had the drive in a tank but could feel the back pressure at the intake on the drive, so doesn’t appear to be plugged. Just finished getting drive off so will have access to the water pump today so will know it’s condition.

 

[Rranger]

Can you think of a reason I have the stream but no water getting to my thermostat housing? I did unhook the hose at the thermostat housing, then hooked a garden hose to that end and forced water backwards and had the drive in a tank but could feel the back pressure at the intake on the drive, so doesn’t appear to be plugged. Just finished getting drive off so will have access to the water pump today so will know it’s condition.

And of course all bolts holding top end on seized tighter than Toby's @#%

 

[southkogs]

In a tank/barrel the Stringer won't draw water. The bulk of the drive has to be submerged, and then the impeller will move the water for you. The fitting in your photo with the hose is to run water into the system when you're on the hard. Barrel won't work.

Mine used to look like a water porcupine when I had it hooked up to the hose. I had water shootin' out all over the place.

 

[kenny nunez]

The bolts going through the cover can really be A PITA. Try heating the outside of each bolt up and down on the cover and exhaust housing area while “gently” working the bolt back and forth. When they break most times they are not frozen in the exhaust housing. One way that I used to do if the bolt broke was to carefully drill with a 1/8” bit midway through side of the cover through the bolt followed by a 1/4” bit to shear off the bolt. Then carefully pry up evenly from both sides. That cover is very expensive so you may have to find a used one if you destroy it.
Please post a picture of the thermostat housing and manifolds.

 

[racerone]

Impeller must be submerged to pump water.

 

[Scott Danforth]

to add to above. the whole drive must be submerged when you first start the motor (raw water pump submerged at least 6-8"), or you need to have the hose connected.

impellers are not self-priming

while underway, the force of the water in the pickups provides enough positive head to get water to the impeller for it to push it to the rest of the system.

 

[Rranger]

I wish I had known you can’t run the motor in a barrel. Manual says squat about it. But so I’m clear when in the barrel I have the tell stream behind that hose fitting. But no water. So when I go to the lake if I have the same tell stream behind the hose fitting, if I remove supply hose at the thermostat I should have water?

 

[kenny nunez]

Re read my post #4. Yes there should be a good supply of water feeding the thermostat housing.
I also sent you a private message.

 

[Rranger]

Re read my post #4. Yes there should be a good supply of water feeding the thermostat housing.
I also sent you a private message.

Thanks, Boat was new to me. When parts show up will put it back together and take it to the lake. It did have impeller issues so was good to take a look.

 

[Rranger]

I was talking to guy on a OMC forum about adding a raw water pump and a sea water pickup on my crank to circulate engine cooling water. An idea I like, if it eliminates changing the outdrive impellor, but does it. What could I eliminate from the outdrive if I went with raw water cooling. There is a language issue so I'm not clear on how the raw water pump affects the outdrive and its maintenance? Thanks.

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[Scott Danforth]

without running the coolant thru the drive, you will overheat it.

not a good idea

even on mercruiser alpha when you switch to the crank driven pump, you must keep the pump in the leg to keep water circulating

 

[kenny nunez]

If you add an engine pulley driven pump and draw water through the bottom just connect the incoming water from the drive with a “T” or “Y” style fitting and of course a valve where the hull connection will be. This way you will be able to continue using the flush out on the pivot cap.

 

[Rranger]

If you add an engine pulley driven pump and draw water through the bottom just connect the incoming water from the drive with a “T” or “Y” style fitting and of course a valve where the hull connection will be. This way you will be able to continue using the flush out on the pivot cap.

Excuse the naive question but how do I benefit from adding the raw water pump if I have to keep the outdrive impeller? And I rely on my temp gauge to tell me if an impeller malfunction by the temp. If the impeller malfunctions and the raw water pump is sending water cooling the engine I guess I’d blow a drive. Am I missing something here?

 

[kenny nunez]

The purpose will be as SD said to keep the oil in the drive cool because the exhaust water is too hot.
As long as the impeller blades are still in place is all that is needed to flow water through it.

 

[Rranger]

The purpose will be as SD said to keep the oil in the drive cool because the exhaust water is too hot.
As long as the impeller blades are still in place is all that is needed to flow water through it.

Sorry I get the impellor would keep the drive cool, but my question is why bother with the raw water pump if the impellor in the drive is supplying water? What am I gaining?

 

[flashback]

other than redundancy 2 water pumps I don't suppose you gain anything..