Shame on me. I turned a blind eye on the engine mounts for too long. The work was one reason, the price for four original Yanmar engine mounts of 1000 Euro was another. By chance, I came across a Spanish-based company called Ellebogen. The offer was superb, the reviews too, and I ordered four engine mounts. The delivery was fast and the contact to the company excellent. In a nutshell, entirely in line with other sailors’ comments.
The replacement of the engine mounts took me almost to my physical limits. The engine compartment is very tight, and disassembling the four mounts after 32 years wasn’t fun. I wrote to friends, imagine you got married two women at once, and you’re close.
My wife helped as much as she could, and after eight hours, we got rid of the old and rotten mounts. The news ones fitted like a glove and were a joy to look at. We aligned the engine to the propeller shaft and were back in business. Before disassembling the mounts, I measured the noise by a tablet app and did the same afterward. The noise level dropped by about 2 dB across all speeds and loads. That was about in line with my expectation. What I didn’t think about were the vibrations. Athene is a steel boat, and the engine is installed under the waterline, so it is quiet by design. After mounting the Ellebogen mounts, I sensed very subtle vibrations in the cockpit – at least someone like me who pays attention. My wife: Don’t know what you’re talking about. On deck, no vibration is noticeable; only the exiting cooling water at the stern is audible. But that’s another story that has nothing to do with Ellebogen.
Conclusion of our experience in stock market jargon: Ellebogen, strong buy recommendation!
Ellebogen describes in great detail the alignment of the motor to the shaft, including a video for illustration.
However, the installation situation on board Athene is somewhat different, as there is a flexible coupling between gearbox and shaft. I installed this a good 15 years ago to compensate for possible minor errors in alignment. In addition, these dampers of Uniflex type decouples motor and shaft to reduce vibrations and thus the noise.
The only problem is that measuring with a feeler gauge does not lead me anywhere because the coupling is flexible. At this point, car repair shops helped me, as they use a clinometer to set the wheels.
And that’s how I did it: Since the stern tube is fixed, I took this as the reference. Next, I put the inclinometer on the shaft and aligned the engine until I got the same angles. Finally, I used a dial gauge and checked the out-of-roundness of the shaft. It is +- 0.1 mm.