High Torque and Snapped Bolts

Everything seemed to be going along as usual. One would think that after completing a project as huge as the engine replacement the boat should do something different, like fly, or levitate, or something of that nature. But it was the same old boat, just a little more heavy in the bow, with some slightly new “furniture” in the foc’s’le because I had to make a new front cover to the engine compartment to accommodate the larger engine. Other than that it was the same old boat, which I guess is a good thing since all I ask for is a sound vessel to pull me through the season.

I was fishing at the Johnson Hill line on the morning of Tuesday, June 19, when my refrigeration unit stopped working. The chilled water stopped spraying through the spray rails around each hatch, but the critical pressure numbers were still displayed on the panel. In seeing this, I gave it an instant diagnosis from the flying bridge; the thousand-dollar side-load hydraulic motor had once again broken its shaft. This had happened a few years earlier, and I was so sure of my diagnosis I didn’t even go down to check out the situation first hand. At the very least I should have shut the unit off, but I didn’t bother doing that, either.

A few hours went by, and as I kept fishing through the flood, the engine died a couple of times as I was maneuvering the Sunlight III around. This was quite odd because my new engine has way more torque to pull its load, and I didn’t figured it would never die — especially without the refer unit running. I should have thought more closely about these inequities, but I was so burned out on boat work all I wanted to do was fish.

A short time passed, and then I noticed a sudden vibration coming from the engine. I pulled the throttle back and went down into the foc’s’le to investigate. I removed the front engine cover and viewed my troubled new engine. It looked all right, except for the fact that the harmonic balancer, a big round hunk of steel positioned at the forward end of the crank shaft, was spinning out of balance, which was anything but harmonious.

After some investigating and prodding, I realized I had snapped three of the four super-strength engine bolts that hold the harmonic balancer, and all the hydraulic-pump couplers, together. When my refer unit stopped working, it wasn’t because the hydraulic motor broke, which would have stopped all hydraulic power going to the unit. Instead the water pump seized up, thereby putting a tremendous load on the hydraulic system, which got hotter and hotter and created so much load that something had to give.

That was why my engine died those couple of times — if it were my old, less-powerful engine it would have been rendered inoperable. But my new, more powerful engine just shifted the burden to the weakest link in the system, those super-strong engine bolts.

I was lucky to have one bolt still intact. I disconnected all the hydraulic equipment, bolted the engine back up with its one and only bolt remaining, and we hauled the net aboard without hydraulics, which isn’t a big deal (we’ve done it many times). From there I idled into the Peter Pan “Nornak” dock to fix my boat’s ills.

The biggest obstacle I faced was not being able to find the right bolts. I drove everywhere, and called everyone I could in an attempt to find the right bolts, but in the end I had to order them from Cummins Northwest in Seattle, which I figured would take about a week to arrive. In the meantime I found three other bolts. They weren’t the proper strength, but in a pinch they would do.

I put them on the engine, but to lessen the load on those weaker bolts I did not run the load-sense hydraulic system off the front of the engine. The fix worked and I was back out fishing on the very next tide. My refrigeration and bow thruster weren’t hooked up, but at least we had our deck hydraulics and an operable engine to get us to where we were going.

The other issue was the seized-up water pump on the refrigeration unit. I simply unbolted the defective pump, dropped it off at Refer Pete’s place, and told him to get it working somehow. He wound up replacing the bearings and a couple of other parts while he was at it, and the whole system was up and running about the same time my bolts arrived for the engine. So by the time the heavy fishing started, this whole debacle was in the past.


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