Yanmar 3GM raw water pump upgrade

[Charlie98117]

I saw some others here who used the YM series raw water pump bracket to reverse the orientation so the serviceable part is accessible without removing the pump and bracket. I did the modification to my engine and made a pdf of the process if anyone is interested in doing the same.

 

[mermike]

Nice mod, I might consider this. Completely off topic, but is that motor in your basement?

 

[Charlie98117]

Yes, I picked it up a couple years back and rebuilt at my leisure. It gets installed this week.

 

[Ralph Johnstone]

@Charlie98117 , do you know if the PN 128990-42151 bracket is suitable for reversing the water pump on a 2GM20F ?

 

[Charlie98117]

I believe so. The 2 and 3 timing cover and raw water pump are identical.

 

[Ralph Johnstone]

I only check my impellor every two or three years but I agree, it's one &^%@!*#$ of a backwards, upside down job which I can live without.

After looking at your install, this will be the next winter project once I complete the relocation of the Espar thermostat in the salon. Then I can work in comfort without frozen fingers. I can also swear better when I'm warm.

 

[Charlie98117]

The only other comment I would add is that my solution to modify the original bracket into a back bracket is a bit clunky. A cleaner and stronger attachment might be made using the YM back bracket (#23 in manual, PN 128990-42160) or fabricating something similar.

 

[Ralph Johnstone]

Will head for the boat today and after finishing up with the Espar, will start laying out a plan of attack for the bracket and see how part #23 fits into the equation.

Thanks for the heads up.

 

[Hello Below]

I only check my impellor every two or three years but I agree, it's one &^%@!*#$ of a backwards, upside down job which I can live without.

After looking at your install, this will be the next winter project once I complete the relocation of the Espar thermostat in the salon. Then I can work in comfort without frozen fingers. I can also swear better when I'm warm.

Ya gotta love it when you come across a project that you can add to your list. Alleviates the winter doldrums.

 

[kloudie1]

Posts from back in the day:
Another New Project That might be of Interest | Sailboat Owners Forums

 

[Charlie98117]

Posts from back in the day:
Another New Project That might be of Interest | Sailboat Owners Forums

Yes, Joker's thread was the guide I followed. However he mounted the new bracket on top of the old and I could not however get the alignment to work following his example, perhaps he had the other pump that came with some engines. This is why I modified the old bracket to incorporate an offset and allow the YM bracket to mount directly to the timing cover case.

 

[Ralph Johnstone]

Ya gotta love it when you come across a project that you can add to your list.

Yeah, yeah, yeah .

And if it weren't for this site, I could go back to my old hobby of hanging around pool halls, drinking beer all day, and be happy once again .

 

[mermike]

P/N 128990-42160 is $189.74 plus shipping from Toad Marine. Yikes.

 

[Charles Erwin]

This modification might not be for everyone. Frequently pump failures end up being a leaking lip seal that allows water into the bearings and the thing quits. (I have done tens of these failures.) In such a case the forward-facing version means you will have to take the whole thing off - bracket and pump - then disassemble that assembly in order to get to the bearings and the seal. Alot more work than the factory aft oriented version.

As to an impeller change just do not fiddle with trying to change the impeller with the pump on the motor - as my friend Ralph seems to favor. Instead, release two hose clamps, unscrew two bracket bolts - the bracket and the pump come off together. Change the impeller on the bench (the galley cutting board probably) and put it back in place. I bet this approach is not more than 10 minutes more (in and out) than the forward faced version impeller change. Not much since you don't change impellers but once in 250 hours' time (1000 hrs. by the manual) anyway.

Tip - I have another separate pump/bracket ready to go on short notice. Just unscrew/release the one that has quit - no matter why it quit - screw on the back up assembly and you are underway.

Charles

 

[Charlie98117]

P/N 128990-42160 is $189.74 plus shipping from Toad Marine. Yikes.

Yikes indeed. Funny it looks simple compared to the pump bracket with a welded gusset plate which is only $62 from my local Yanmar dealer. Perhaps my hack of the old bracket isn't so bad after all.