When I bought my J30 in Hood River, Oregon last fall I had a very limited amount of time to get the boat out of the marina there. The sellers didn't want to pay for another month of moorage and I wanted to get going too. I really wanted to have a bunch of spares ready for the 95 mile downriver trip, but the serial number plate is missing and according to the local Yanmar marine experts you really still need to have the impeller in your hand to identify it correctly. I even said that I would buy all the close possibilities, but he still declined saying there were just too many to to bother with that approach. So we ran the boat downriver and it ran just fine the entire time as well as the trip to the haul out, for a total about 115 miles. I have no idea how long this pump was in this condition before I bought the boat.

Well today I was looking at that sturdy little motor and decided that I would pull that pump apart and go get the new impeller, belt and a gasket. I can't say I was surprised when I opened the pump up, but I do believe I was extraordinarily lucky this time.

This is a pretty easy thing to service and I don't think I need to tell anyone what happens when no water gets through the system. So spend the 15 minutes it takes to break this little pump open to inspect the impellers and the brass plate that covers it, because the plate is a wear item too.

So I plan to get the parts to rebuild this pump and to buy a complete new pump. Probably will never need it, but it would really suck to need it and not have it.

If you don't have an expert dealer for Yanmar, I recommend Gallery in Seattle. I'm a retired trailerable boat mech from Seattle area. I use them as I am retired in Kona. Their number is 206=547-2477. Make sure the impeller will slide freely on the shaft or it will not center in the cavity and may not pump. You could use this as a chance to replace the bearings and seal. If you need help, I'm at 808-333-5068.
Bob

I spent some time trying to remove this old impeller and it actually seemed like it was bonded to the shaft. Could be age or heat or ?? I think the Yanmar dealer here in Portland is competent and they are close.

I'm still amazed at how small this pump is.

You may have to dress the burrs on the shaft to get the new impeller to slide on.

Bob

Bob,
The new complete pump was a mere $450 and for them to rebuild mine was even more with their labor rate. So I will be adding pump repair to my to do list. I see the parts break down for this pump, there must be a metal sleeve under the rubber impeller that I have to remove before I can get the shaft to pull through the body. Is there any trick to doing this? Maybe some gentle heat? This is not a complicated device, it is just one I am unfamiliar with. I may have to buy the impeller to see what it looks like before messing with this. The pump wasn't leaking or doing anything else interesting. Had I not disassembled it I wouldn't have known it was gunnybag.

I also see that guys have simply polished the shaft before rebuilding rather than replacing this $95 item. Basic rebuilding of this thing is not expensive at all, if you don't buy the expensive parts and you can figure out how to dismantle it.

Buy a pair of reversable snap ring pliers at an auto parts. Other tools are just common. a 3/8s brass rod is good to tap out the shaft and bearings.

Bob

Yes, the impeller has a metal sleeve with a pin going through it that engages the slot on the shaft. It takes a little coaxing to get off, but with the correct needle nose pliers, it will come free. You could spray it with penetrating oil if needed.

GL,

-Chris

Ok everyone thanks for the help. The needle nose just couldn't get the sleeve off. Had to resort to some channel locks and carefully rocked the the thing off. It was pretty stubborn. Then I got the Dremel tool out and lightly cleaned out the cavity and the shaft using a tiny wire wheel. Then spent most of the rest of the time cleaning the build up off the inlet and outlet mainly so I could tell if they were leaking in the future. Installed a new cover used some medium thread locker mainly to seal the threads, again for future removals. Painted the pulley and bracket and reinstalled the thing. That's when I started noticing the wrong hose sizes and various other annoying details that can get fixed another time.

Plan is to pull this whole thing next year and do a complete rebuild. I suspect we use the motor here more on the river than other locations, because of the 4+ knot current that seems to only go in one direction, day in and day out, unlike the tide.

So nice to see that J30 owners are still helping newbies. I have had my boat since 1994, but I still lean on big brothers for advice. I think I'm on the end of the second round of repairs/replace... so at least I have some hands on to call on. I currently have the tranny off, and all parts aft of that to the prop.

BOB, Last Fling... think we can discuss from one island to another? I'm in Virgin Gorda, BVI. I'm on skype J30JDOE

the Redhead

The final chapter in this story is that today I bought an entire pump. After fully rebuilding the old pump complete with bearings, seal, gasket and a backing plate the old pump would simply not prime itself. If I put a bucket of water above the engine and primed the inlet line it would pump like crazy and everything was good. Put the bucket down by the engine and nada it couldn't create enough suction to pull any water in.

After installing the new pump everything is good to go. The dealer was explaining that not only does the impeller need to be in good condition, so does the body itself. Once it gets worn beyond a certain point a new impeller is not enough. He also shared a piece of advice that I think could be really helpful to anyone doing a rebuild and that is to put a squirt of dishwashing soap in the pump before installing it. This can keep you from burning the new impeller up while starting the engine. He was also saying that these impellers should be replaced every two years, or less in some environments. Here on the river we have to remember that the water is carrying silt and that is going through the pump and silt is an abrasive, so our pump life may not be the same as the rest of you all.