Equipment breakdowns are inevitable, and not just on boats, some due to age, some to neglect of the previous owner, and some my own fault. I smiled when I saw a forum member’s signature: If it ain’t broke, it will be when I fix it. There is much truth in this, especially for the Jack-of-all-trades boat fixer-upper.
The biggest problem so far has been the 6.5kw Kubota generator.
It all started when I smelled shellac coming from the control box, and discovered the circuit board insulation completely melted down. How it continued to work I don’t know, but it did—that is, until I found two unattached wires and decided they should be joined together—wrong, big mistake! When I started the generator engine it immediately started smoking and nearly chocked me, until I managed to switch it off using the manual lever.
I had shorted the stator coils and there was no option but to buy a new generating section. I got one wholesale from the manufacturers, but it was still $2,200 (“whata mistaka to maka” - that’s a British thing from Allo Allo a silly BBC series). I did manage ti get $20 scrap for the old bits though.
I carefully dismantled the genny and made notes how to reinstall the new one. It actually was not a very difficult job, because I didn’t have to disturb the heavy engine section—a bit like rebuilding an electric motor, just bigger and heavier. Happily all the machinery on a Down East 45 is pretty accessible directly below the saloon floorboards.
When it was all put back together I started the engine and we saw 125 volts flick on to the meter, fabulous!
A month or two later I decided to inspect the raw water pipes on the generator engine. This had always run warm under load, and some pipes were only ½” diameter, when the spec’ calls for ¾”. Inspection revealed many pipes and waterways encrusted to less than half their diameter, so it needed attention anyway.
You would think changing ½” pipes for ¾” would be simple enough, yes? But not when you temporarily bridge the anti-siphon discharge pipes then run the engine and leave it for weeks while you go on vacation. I didn’t know any better, but without the anti-siphon, sea water can filter back into the cylinders.
So when I came to start the engine it would not budge - until I removed the injectors and shot a stream of dirty black water all over the ceiling.
The first test was obviously compression, which confirmed my worst fears: # one cylinder 85psi, # two 105psi and # three 125psi. A small diesel like the Kubota needs about 350psi in order to fire. Clearly, the piston rings had seized, so removing the head did not initially show anything wrong. I had to inspect at least one piston, which was easier said than done, because the whole assembly weighs about 350 lbs.
I rigged a four part tackle through the saloon hatch and hoisted the motor and it’s generator section into the upright position, so I could unscrew the oil pan. This was encrusted with about half an inch of old dry oil, which had to be scraped away with a chisel
I unbolted one connecting rod and withdrew the piston to find the rings completely encrusted to the piston, I therefore decided to buy new pistons instead of just fitting new rings.
The first rebuild procedure was honing the bores, which I did with a Flex Hone. This is a funny looking devise—like a Dandelion stem—which you ream up and down the bore on an electric drill. After this the new pistons and rings slid easily into their clean bores, and new big end bearings completed this operation, closed off by replacing a nice clean sump pan.
Lowering the machine was a lot easier than hoisting it, but it still took me another day to refit the head and all pipes and electrical devises. This included three new exhaust valves, and drilling out and re-tapping a new water drain cock into the block, which has clogged up completely..