Our trawler is powered by a single Lehman 120. These are classic engines found in thousands of vessels throughout the world. They are extremely reliable, durable and simple to work on. They will chug along at low rpms for thousands hours. They do have two peculiar traits though.
One oddity is that you have to change the oil in the injector pump. The other is that the exhaust elbow is guaranteed to fail at around five years. It’s cast iron. It has saltwater passing through it. It rusts out eventually and develops a hole in it. This is usually on the bottom where you can’t see it developing.
Our is well over five and overdue to be replaced. I noticed a lot of rust below the elbow, collecting on the heat exchanger. I ordered a new elbow along with a gasket and new bolts. There are only four bolts. No big deal, right?
As with many boat jobs, something that should take an hour or two has stretched out over three days now. The job still isn’t finished. Here’s the old one, finally removed. It had a pin hole surrounded by rust. That is – until I beat the living daylights out of it with a hammer.
Notice the bottom right bolt hole. That bolt refuses to come out. I couldn’t fit a socket on it, until I made the large hole with my trusty hammer. Who knew there were so many uses for a hammer on a boat? Day one consisted of removing three bolts, then cussing at the fourth for a few hours.
Day two consisted of acquiring special sockets for extracting pesky, slightly rounded bolts and trying again. Nope, nope, and nope.
Day three consisted of acquiring a torch (Mapp Gas), and heating the stubborn bolt. Still nope. The local mechanical guru in Boot Key Harbor (Diesel Don), attempted to cut out around the bolt with a Dremel Tool and a tungsten carbide bit.
Almost worked. No cigar. We did manage to get some penetrating oil into the threads at this point. We waited over a beer, then tried the socket again. PLING! Broke the head off the bolt. Bottom right, now painted red:
The only good thing is that it didn’t break off flush with the exhaust manifold. I’m soaking it in Sea Foam Deep Creep overnight. We’ll see what day four brings.
Meanwhile, the new elbow waits patiently to be installed:
The day a boat repair/project goes simply and smoothly and faster or easier than anticipated . . . well, when pigs fly, hell freezes over, etc.