Starting Merc I/O w/ thru hull raw water inlet

[FreeBeeTony]

I am looking at a boat (24' Grady Offshore) with a Merc 260 (5.7L) I/O. It's FWC'd and the raw water inlet is through the hull with the engine mounted raw water pump. How can this be easily rigged so I can start it out of the water with or without the drive connected. Is there a fixture of somekind to connect a hose to the thru hull fitting like the muffs on a O/D?<br /><br />Also.........when the pump is not used in the O/D, is it still used to cool the O/D? Or is it eliminated altogether?

 

[WillyBWright]

Re: Starting Merc I/O w/ thru hull raw water inlet

Some mechanics will unwisely remove the water pump in the drive. That also cools the upper gearcase of the drive, so it should be left in service. I've seen valves T'd into the feed hose from the thru-hull to allow for a hose connection.

 

[loghomer]

Re: Starting Merc I/O w/ thru hull raw water inlet

I have a 5 gallon bucket with a hose fitting drilled and glued into the bottom, However my engine sucks up the water so fast that my house hose cannot keep it full. It will draw 5 gallons in about 30 seconds, so I am constantly turning off the engine to let the bucket refill

 

[FreeBeeTony]

Re: Starting Merc I/O w/ thru hull raw water inlet

How is the water getting from the bucket to the thru hull fitting?<br /><br />I just realized something else......if the O/D was connected I would need 2 sources of water....1 for the O/D and 1 for the thru hull fitting.........

 

[rodbolt]

Re: Starting Merc I/O w/ thru hull raw water inlet

yep<br /> I made a modified plunger for the seawater pick up to the engine and the flush muffs on the gearcase and a y valve from the hose. its common with some boats<br /> but if you have an impeller in the drive and dont cool it when running it will melt the lower base and create a leak in the drive. use a hose barb where the plunger handle goes and a piece of siff wire . I use old control cable wire. poke the wire therog the plunger with a J hook on one end. hook the J over the seawater intake grates. then slide the plunger over the intake and secure it with vice grips on the wire.

 

[FreeBeeTony]

Re: Starting Merc I/O w/ thru hull raw water inlet

That's very intuitive........... <br /><br />And I bet it works great!<br /><br />Nice idea!<br /><br />What if there isn't enough water for the sea pump?<br />Does it get damaged like the impeller in the O/D?

 

[waterone1@aol.com]

Re: Starting Merc I/O w/ thru hull raw water inlet

You can buy two different types of "muffs" for that situation. They make one similar to Rodbolts that has a spring loaded hook, they also make one on an adjustable pole that wedges from the ground up to the through hull.

 

[rodbolt]

Re: Starting Merc I/O w/ thru hull raw water inlet

yes the engine mounted pump will roast just like the drive mounted pump if not supplied with water. the flusher on a pole works well. beaware that if the boat is on a trailer its prone to fall off when walking about the hull and the boat moves on the trailer springs. also be aware that if you just place the pad of the telescoping pole on the dirt the water has a tendacy to soften/wash the dirt away and the flusher falls off again.<br /> dont ask how I know

 

[Buttanic]

Re: Starting Merc I/O w/ thru hull raw water inlet

If the pump suction has a seacock which it should, simply put a tee in the hose between the seacock and the pump, put a valve in the Tee with a garden hose fitting on it. To flush connect the hose, close the seacock and open the valve on the tee and crack open the garden hose