My winter has been filled with time taken to document the rebuild of Rhapsody’s Yanmar 2GM diesel engine. I put together a website that has pictures of the rebuild along the way, along with some of my editorial comments. There is a 2nd page that has helpful Yanmar 2GM links.
http://j30rhapsody348.blogspot.com/p/rhapsody-index-page.html

This 25 year old engine now looks brand new. It is ready to install back in the boat and reconnect the linkages, hoses and electrical system. I've also recirculated the fuel using an electric fuel pump and Racor filter to get rid of "Diesel Bug". I'll do a final recirc this spring using a 2 micron Racor filter, then reconnect the fuel lines to the engine and bleed the system. It should crank right up!

Hopefully there is information here that will help others who want to tackle their Yanmar. This is a fairly simple engine, compared to the race car engines I used to build in the 70’s!

Bill
Rhapsody J/30 #348

Wow... Bill you've done a great service to the J/30 community by documenting your engine rebuild so thoroughly. Please accept my thanks for all of your efforts. I have a couple of questions. First, just out of curiousity, did you check the compression on Rhapsody's engine before you pulled it apart? If so, how did it compare to specs? Also, did you have the high pressure injection pump serviced while it was off the engine?

This spring, I may try the vinegar trick to get rid of some of the scale on Mondial's cooling passages.

Joe – thanks for the comments. Here are some responses to your questions:
Compression – I didn’t check it, because I really haven’t had a problem with power or burning oil. Even though the engine is 25 years old, the number of hours we put on these engines is negligible compared to a stink pot.
High Pressure Injection Pump – all I did was flush it and replace the seals. Kept the same number of shims (original) under the case so as not to change the timing.

Flushing your Yanmar – I used a hammer, chisel and Dremel tool and blew the chips out with an air hose to remove significant scale in the water passages before reassembly and flushing. Depending on the age and amount of scale you have, you may want to use a much stronger acid (Muriatic) if you are not disassembling and mechanically removing the scale. The other way to approach this is leave your engine in the boat but remove the heads. I found most of the scale buildup in the upper section (heads, water manifold that holds thermostat, aft zinc holder). These can be taken home and cleaned on a workbench. The block can be cleaned in place, although my basement was much easier to work in than cricking my neck on the boat.

Bill

I added another page for oil changes, and also put links in for the new Dodger installed in 2006. This oil change page describes the route I took instead of drilling into the oil pan.
http://j30rhapsody348.blogspot.com/p/yanmar-2gm-oil-change-suggestions.html

The time has come where the Yanmar on my 1979 J30 needs a rebuild. The power is not as stong as it once was (a stiff headwind and waves can make a very slow situation) and seems to be burning oil. My question is, has anyone paid someone to pull the engine, rebuild and re-install? Any idea what a job like this might cost? Just looking for a comparison number as I find the right Yanmar person for the job.

Why not pull the engine yourself and reinstall it after someone does the rebuild? We used the main halyard and a twing on the boom to position the lifting point over the aft end of the companionway. I built an engine stand from 2x4's. Having gone through this I would have two people inside to help position the engine on the stand in the boat. If the mechanical part of the engine rebuild is too far over your experience level, you can probably save a bunch of money doing the work of disconnecting hoses, harnesses, linkages, shaft and engine mounts, then pulling the engine yourself. Go to my website listed above and download the Yanmar manual to scope it out. My rebuild did not include rings or bearings because I wasn't loosing power and not burning oil. Cost including all new hoses, gaskets, etc. was around $400 and lots of labor of love.

Bill

Here's a tip for anyone who has excessive engine / shaft motion and shaft seal leakage. I replaced the engine mounts in 2007 with PYI Engine Mounts #800040 (5/8" stud - 4" hole pattern, rated for 30 - 91 lbs. Long story short, these mounts did not have sufficient load capacity and resulted in some spray off the dripless shaft seal at higher RPMs due to excessive shaft movement with engine vibration.

The combined 2GM engine / transmission weight is approximately 275 lbs. I assumed equal load distribution, and subsequently learned the distribution is approximately 40% forward, 60% aft. Early this season I replaced the aft mounts with Bushings Inc. DF-2205-2 and noticed significantly reduced engine motion and resulting spray. The front of the engine still showed lots of motion at idle.

Well the straw that broke the camels back was returning through the Cape Cod Canal from the NAs. I limited RPM to minimize the inconvenience of cleaning up the spray from the shaft seal in the engine compartment, when I really could have used max RPM to power through the chop in the canal.

Upon return I ordered two more Bushings Inc. DF-2205-2 mounts and replaced the front mounts last night. The engine now has very little motion at idle, but I don't notice any more deck vibration than previously. The new mounts are rated for engine weights 150 to 450 lbs. I'll do a high speed run this weekend to verify all shaft seal leakage has been eliminated due to vibration.

So - if you replace your 2GM engine mounts, the ones that work for me are Bushings Inc. DF-2205-2. I also used aluminum plate and built shims under the mounts so the adjustment nuts are near the bottom of the stud. I figure this reduces the stress applied to the mount. Pictures of the two mounts are shown below.

DF-2205-2 Engine Mount. . . PYI #800040 Engine Mount

.

Bill,
Thanks for the mount update, I will keep the part number in mind. The yard checked mine last year and declared they were still OK. On another note I finally installed the Racor filter per your photograph. I noticed you have a small inspection port in the forward engine area. Was the port a water fill fitting? Did you have to cut the tail piece down or is there enough clearance below? What do you use the port for?
Thanks,
Rob

Rob,

That was an attempt to gain inspection to the "hidden bilge" in this old thread. Don't waste your time installing that inspection port.

I built up the wooden bracket to mount the Racor on so there is easier access to unscrew the bowl on the bottom of the filter.

Thanks for the heads up on the inspection port. I'll return it although I always wanted a water tank fill on deck. Has that been done by anyone?

I made a new wooden mounting piece and have at least 2" under the filter to swap out the element. The bleeder pump is a delight, much better than the lift pump on the engine. A picture is in order go to my blog,I'm not smart enough to post a photo on the forum. The coolant hose coming from the strainer is interfering with step a bit. It needs to be moved upward. It is so hot down in FL right now I can only work in the AM with a sunshade and box fan. By noon I am toast.