SailNet Community - View Single Post - Removing the Yanmar diesel from my boat *many pictures*
View Single Post
post #1 of Old 12-03-2010 Thread Starter
Sailing to surf
Beersmith's Avatar
Join Date: Nov 2008
Location: St. Augustine, FL
Posts: 208
Thanks: 1
Thanked 0 Times in 0 Posts
Rep Power: 8
Talking Removing the Yanmar diesel from my boat *many pictures*

Background: I am rebuilding my 1975 Downeaster 38' Cutter. I write about it here. If you have any tips regarding what I should do with the engine out, please chyme in!

With the weather cooling down, I decided it is time to focus my efforts on the monolith that is the Yanmar 4JH2E - my diesel engine (1991; 1,061 hours. Runs great, is cosmetically challenged, a few bad parts). Not just the engine, but the entire engine room needs work before we splash.

My plan for the engine is to completely clean it off of old paint and rust, replace all hoses and clamps, replace the rusted and busted air intake, and do some general maintenance on the engine. I might go as far to replace the seals/gaskets, refurbish the heat exchanger, have the injectors inspected, and who knows what else. With all of that in mind, I decided it would be easier to just pull the engine so I can have easy access to all of the engine itself, and the entire engine room for cleaning (room and bilge), rearranging, and painting.

Engine and engine room before any disassembly:

Here is the coupling, stuffing box and shaft before any disassembly. Note all of the rust, especially at the set screws.

I started by applying penetrating oil to the coupling bolts, set screws and the shaft itself every day for about a week. I then needed to start removing the exhaust hose and muffler to gain access for wrenches to fit down there.

Here is the exhaust and muffler above the shaft:

With some brute force, the coupling bolts came off eventually. The set screws took a lot more effort, blood, and sweat to get out. One of them was easier than the other, both took vice grips to get them to budge. Here is the coupling after separation, and vice grips on the set screws.

Below the muffler was a plywood panel that capped the space where the stern tube is located. This wood was pretty much disintegrated thanks to the stuffing box leak. I'm pretty sure the exhaust leaked down there as well.

I then set out to remove the coupling from the shaft. The recommended trick is to set a spacer (I used a socket) set between the couplings against the shaft, and then crank down on bolts connecting the coupling halves. Cranking down on the bolts evenly would then push the shaft out. Unfortunately, I found that I have very little clearance between the transmission and transmission coupling to allow any bolts to be screwed down. I might be able to get it done by cutting some bolts to a precise size. I then realized that it was silly for me to be trying this hanging upside down in the engine room when I plan on pulling the engine out anyways. I'll attempt to remove the shaft coupling once the engine is out and I can do it in a more comfortable setting.

After getting the coupling separated, I performed the following to prep the engine for removal:

-Remove refrigerator compressor and its mount
-Disconnect all hoses - water feed, fuel feed, fuel return, exhaust
-Disconnect wiring harnesses, starter battery wire, grounding wires
-Remove alternator (want to replace it, and it gave some extra room to get to wiring and mounts)
-Disconnect coolant water expansion tank and hose
-Remove belt
-Remove air silencer/intake (needs to be replaced, flimsy and always falls off anyways)
-Remove engine room side insulation (for a little more room to work with)
-Remove motor mount nuts. The rear motor mount nuts were so rusted and frozen, I needed to use a combo of drilling through them and a dremel cutoff wheel to get them off. They were easily the biggest pain of this whole process.
-Disconnect the transmission control wire
-Disconnect throttle control wire
-Disconnect tachometer wire

Side panel insulation before removal. In poor shape

Front stbd mount. This one was easy

Front port mount. Needed to remove the fuel tank hoses to get to it. Post alternator removal as well.

Mostly disassembled

Engine room

Things that have come off

View from above after removing companionway stairs

Up comes the engine!

Will it fit!?

Piece of cake


Engine room post removal. Cleaning this place up is one of the big reasons I wanted it out of there.

Notice the piece of motor mount lying there. The aft, port mount rusted in half!

The Abyss (aka, the bilge). Cant wait to clean that out

The shaft

Packing nut with loose flax packing. This is what allowed water to spray all over the engine room. Can't blame it for failing after seeing the poor condition of the mounts.

Engine all cosy on the ground, ready for work.

Cant wait to clean and paint the beast.

My boat rebuild/sailing blog:
To view links or images in signatures your post count must be 10 or greater. You currently have 0 posts.
Beersmith is offline  
Quote Share with Facebook
For the best viewing experience please update your browser to Google Chrome