water pump hose routing on m2-12 engine

[fastmover]

I just replaced my sherwood raw water engine pump with the oberdorfer n202m16. It mated up to the engine block attaching with the same two bolts. I had to shorten one of the barbs on one of thexchanger on the enginecause the in and out ports are closer together on the new pump. I have some pictures if someone wants to how it fits.

But now I need some help as I did not take a picture of the hose routing to the pump. One hose goes from strainer at thru hull fiting to one side of pump and the other hose goes from the heat exchanger on the engine to the other side of the pump. When I disconnected the hoses I didn't notice which hose goes where. Since both pumps have same orientation can someone tell me which port the water intake goes to. when looking at front of pump the two port elbows are pointed downward and to the left (starboard) side of boat in what be the 8'oclock and 7 oclock position.

 

[Stu Jackson]

The Oberdorfers I've seen have the inlet from the rw strainer at the 7 position and the hose to the HX at the 8.

You can easily check it yourself.

Connect the rw inlet from the thru hull to the 7 position and connect a hose into a bucket with the other.

If water pumps out, you'll know.

That's what I'd do.'

Good luck.

 

[fastmover]

The Oberdorfers I've seen have the inlet from the rw strainer at the 7 position and the hoseclockwise or countere HX at the 8.

You can easily check it yourself.

Connect the rw inlet from the thru hull to the 7 position and connect a hose into a bucket with the other.

If water pumps out, you'll know.

That's what I'd do.'

Good luck.

Thanks Stu for the reply. My understanding is that the pump is designed to be used on multiple engines and turn either clockwise or counter clockwise and I thought about doing just as you suggested however at the moment I have the hoses connected just opposite of what you suggested. I was hoping someone with this engine could take a look for me as I would hate to ruin the impeller trying to find out. If I could figure out how to post a picture from my camera to this site it might help

 

[hewebb]

On my Universal M-12 the raw water goes to the Oberdorfer pump on the upper inlet to the left of the two fittings (7:00 location) The one to the exchanger goes on the lower fitting or the one to the right (6:00 location) it has a 90 degree elbow into the pump.

 

[fastmover]

That's the way i hooked up the hoses but haven't run the engine yet

 

[Stu Jackson]

fast, you won't hurt the impeller if you just try it for a very short time, which is all you'll need. Many of us may choose not to admit it, but have forgotten to open the thru hull seacock for the raw water sometime in our sailing lives, and the impellers have survived.

This thread proves that what we may have on our boats may not be what you have on yours. YOU need to figure out what YOU have.

Good luck.

 

[fastmover]

Thanks Stu and Hewebb
I did as Stu suggested and disconnected the water hose at the heat exchanger started the engine to check the flow. I had guessed correctly. It turns out that on the m2-12 the raw water inlet is the upper port 8 oclock position and the inlet port below that the (7 oclock) position goes to heat exchanger. This would be the same on either the sherwood or oberdorfer pump. Maybe this will help someone else with this engine.