3ym30 fresh water pump belt

[Ken Honeycutt]

Has anyone changed the fresh water pump belt on the 3ym30? Looks like it could be bear. Also is there anyway to adjust the tension? I've adjusted the belt tension on all sorts of engines but swear I just don't see how on this installation. Even asked a yanmar dealer at the boat show and he couldn't figure it out either even with the engine sitting in front of us.

 

[Mark48]

I have changed the belt on my 3ym30 and it is not a big deal. Look at the picture in the recent posting "please share H 34 bare sole underside" it shows the engine and the belts very clearly. I think one does have to remove the altinator/circulator pump belt then loosen the bolts holding the freshwater pump and remove. Use a large screwdriver or prybar to place tension on the new belt and tighten bolts. Careful not to over tighten.

 

[Scott B]

I've changed both. There is a pivot slot on the alternator for the fresh water pump and the sea water pump bracket has a pivot slot. Not overly difficult to change either.

 

[Ken Honeycutt]

Mark, Scott, thanks for the info. I misstated when I said fresh water pump. I meant seawater pump. I've changed the alternator belt with no problem. When I'm back on the boat today I'll look for the pivot point on the seawater pump. The belt is a little loose and I've got a 90 km sail back to Chicago tomorrow. Winds look good for now but I will have some motoring.

 

[Scott B]

Yep, I do that mistake too. To change the seawater belt you have to remove the alt. / freshwater belt. Make sure you have the right belt. I ended up with a slightly larger one previous and was too sloppy.
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[FONT=&quot]Yanmar Water Pump V-Belt M19 part #104511-78780[/FONT]

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[Scott B]

Looking at the parts catalogue, appears pivot slot is on lower side of bracket under the pump. Fig. 13.

 

[Ken Honeycutt]

Thanks again Scott. Now I see what's happening. Should have looked at the manual before. That slot is hidden from view when you look at the pump.

 

[Scott B]

Well, you know what they say when all else fails...... rtfm. But it's more fun to ask on the forum