Just curious, what's the problem with the Farymanns. I've got one and so far (5 years) no problems at all. Just lucky maybe but interested.
A few issues:
1. They run at 3600rpm. This causes a lot of vibration and things shake loose and break. Probably wear faster too, but few log enough hours to really test durability.
2. Noise. While they may not rank that high on a dB meter, the noise quality is offensive, at least to me. A high note "buzz" vs a "purr" of a 1800 3cyl.
3. Water intrusion. Chronic problem on some, especially the Panda. Theory is that on shutdown, engine kicks backward off compression on last rev and sucks wet exhaust into cylinders. Valves and piston/liner corrode.
4. Panda specific: If water leaks inside enclosure, wet insulation in contact with oil pan rots it out.
5. Control systems- Most using this engine have strange controls that are difficult to troubleshoot when they don't work.
When I was deep in the generator business, we had a small pile of dead Pandas.
Not all the brands using the Farymann engine came into the shop as failures, but there are enough downsides to avoid them.
On some boats the size/weight benefit of these made them the only viable option. I simply refused to install one as I did not want an unsatisfied customer down the road. Those boats went elsewhere. This was for new installs, if it was already in there we would try to fix it or replace with a better unit.
