2011 R-27 Yanmar Sea Water Impeller Replacement Interval

[Salty7]

Thanks both Tim and Mike, invaluable information. On the shower sump box. Yes, a total pain. When it comes time, I have a fix. Remove the shower box cover and replace the float switch with a solid state switch, discard the pump, run a pick up hose into the box and anchor it just off the bottom of the box, replace the cover and use a Whale gulper shower pump, activated by the wet switch and connected to the discharge hose, to empty the box. I did this on my last boat and it never failed. No problems with soap, hair or grunge, they are an unstoppable pump. Very often regular float switches sink due to the weight of hair and/or soap, they are just the wrong switch for the job and the little pumps in those shower boxes are very weak for this application. I have already looked at this and I think the pump can be mounted under the sink. Getting the back outboard screw off the box cover will be fun but I have the tools for that. Wonder if the designer ever cleaned that box out himself?? Once the box has been modified this way, once a year you can remove the lid (I suggest leaving that impossible 4th screw out) run water into the box and take an old toothbrush to scrub the grunge out. The box will self-clean in no time and run at least a year before needing another cleaning.

 

[Red Raven]

Change the shower sump lid screws out for thumb screws to make it even easier.

Curt

 

[Boatdreamer]

Thanks Salty7 and Curt, both are great ideas. Cleaning the shower sump has been the most difficult job I’ve done on Gratitude, it took me over five hours and a lot of blood to get it done. I think I’m going to use a finer cap over the drain to trap hair before it goes into the sump box and install a manual button so I can eliminate the float switch then I can drain it as needed. On a boat it’s always something but we love our Ranger Tugs so we deal with it! Sorry to have highjacked this thread.

Tim and Donna
Gratitude

 

[j&lgray]

Since we are talking shower sump box maintenance. We live aboard and use the shower nearly daily. The box gets cleaned only once a year. What do we do between cleanings? Use a very fine hair trap filter over the drain. Then, once a month pour a straight vinegar into the box into the pump runs, then do it again; wait a few hours and then run straight hot water down the drain for 15 minutes.

 

[GaylesFaerie]

That's awesome if your arms are long enough and fingers thin enough. There is no way I can dismantle the pump from the top, I can barely get my hand around the front of the engine, let alone get a tool in there to take the pump apart. Did the guy in the photo take the pump off or take the pump apart in place? I am able to take the pump off without taking the cave apart but I cannot put it back on without access from the front. There are other things on the front of the engine which will need service one day so it is highly likely I will modify the step. It is good to know someone out there can actually replace the impeller without going through the front too small access hatch. Thanks for posting.

As I stated above, on the R-27 or 25 SC you are doing unrequited work by modifying the step. Just make the opening wider on the front of the step and use 1/4 inch starboard as a frame to cover the larger opening and then screw the hatch door to that. When you are replacing the impeller you remove the starboard (four screws, one in each corner) with hatch door attached. Then cut the interior slide out panel as described earlier. This modification will take at the most two hours with maintaining the integrity of the step. I can get my whole torso in there (5'-10" and as heavy as 200 lbs.) with this modification and work on the entire front of the engine.

As a newbie owner I've not done an impleller change yet (coming next Spring) but reading about what a pain it is makes me glad for the modification that came with my 2012 R27. See pics below. It seems to work well, no rattling under way, solid to step on, and looks like part of the boat design. The previous owner had it done by a boat mechanic and I don't know what the cost was but it looks like a professional job. You not only get access to the front of the engine but the forward bilge pump and bilge. Personally, I would much rather take the time to disassemble the cave panels than contort and curse and bleed through a lesser opening. That said, I may still contort and curse and bleed but hopefully much less.

Step Latched in Place: https://photos.app.goo.gl/vykvAJy8ok7NdmKK6
Step Open with Cave Board Removed: https://photos.app.goo.gl/AZfYve8M2Pf9GZAo6
Step Open Close Up to Engine: https://photos.app.goo.gl/TAAr73AcN61advmo9

 

[Trisailor]

I replaced my impeller for the first time about a year and 100 hours ago. Thanks to Knotflying's instructions from this forum, it was not too onerous a task. Took about three hours for the first time without a helper. Even with short arms, I ended up on top of the engine like Boatdreamer to get to the outboard bolts for the pump cover. I was able to do the rest from the cave side of the rear bulkhead by laying on my side and reaching in. I have yet to modify my step. That is on the planning list.

 

[knotflying]

If you are thin enough ( I am 5'-10" & 185 pounds) widening the opening and then installing a 1/4 inch thick starboard with the access door in it works perfectly. With the mod I explained above I have the same access without the step modification. I can see and reach all four bolts from the access. I can get both shoulders in the opening.

 

[Skeeter]

So what does an impeller look like that has 400 hrs on it? Does anyone take this to 1000hrs on a Yanmar? I just attempted to remove the impeller on the Yanmar 180. Took the engine covers off for a little room and removed the belt with a belt removal tool. Managed to get 3 of the hex bolts off after a lot of effort and then camed-out the head on the 4th one. I had previously had a marine service do some repairs and they replaced the impeller while the engine was out and torqued the hex bolts so they would never come off!! Someone else mentioned this as well. Make sure they put some anti-seize compound on the bolts and don't over tighten. Will have to have a marine service lift the motor out to get at the 4th bolt. Unbelievable that access is near impossible.

 

[knotflying]

Unfortunately, it sounds like you are going about it incorrectly. Best access is from the front under the step. removing the top covers is of no advantage. I widened the access hole and can get in and see everything. I can do the whole job in about one hour. Yes, anti seize on the bolts is recommended. Which bolt is rounded?

 

[Skeeter]

These are hex bolts. Took a 50foot lb air wrench to it finally after no luck with a 20" extension socket wrench and it rounded the inside corners and bolt did not come out. Had sprayed it with several lubricants a day before. So will have to remove the whole water pump, unless you have a better idea. The bolt is the left upper looking at it from the step.

 

[PanaSeaAh]

Did the same mod on the floor as Scross showed in his photos Jan '20. R25 with a MercCummins. Owe him a big thank you for those photos and description. What a huge improvement! 😀 Better access to belt, water pump, tensioner, idler pulley, forward bilge pump and the secondary fuel filter. Never could get fwd bilge pump out before. Cut 2 1/2" off floor with oscillating saw almost full width. Added 1 3/4" teak "ledge" to the step face at the floor level to cover the cutout with enough overlap for a foam gasket. Cut water pump removal time more than in half.
Huge savings on bandages (not an exaggeration). Recommend that you sand the cut fiberglass edges smooth also.