Where are you planning to sail?
I have worked with Volvo
, Vetus and Perkins engines on sailing yachts in ASIA
Volvo and Perkins proved the most reliable but Yanmar came close behind.
Perkins was easiest to fix myself.
Yanmar benefits when sailing in Asia
(I do not know about beyond Asia) because parts are very easy to obtain in most engine parts stores as these engines are used extensively in agriculture.
If you have time on your hands then Perkins parts are easy and generally less expensive to obtain from most engine parts stores but sometimes, for older models, you have to order overseas and wait for the courier pack.
Volvo parts are almost always not available locally but can be ordered (usually the longest wait time) and always the most expensive.
Vetus parts very difficult to obtain except by courier pack from overseas.
BUT, AFORE YE GO SAILING!!!
Always put some oil
treatment in the engine, something with molybdenum disulfide (MoS2) - in the UK "Molyslip", in Germany
"LiquiMoly MoS2", in the US (old brand name) "Moly BlackGold".
1) because sailing yacht engines get used very little, they sometimes go months between uses and all the oil
thoroughly drains to the sump so, when the engine is started there is a lot of dry-metal on dry-metal friction/wear . . . what MoS2 does is to coat all bearing surfaces with MoS2, which acts as a metal-bonded super-lubricant even when started after months of idleness.
2) if you lose all your oil then the engine probably has enough metal-bonded lubricant to get you out of trouble.
I have had two engines lose all oil while in operation (for different reasons), the first one had no oil additive, quickly seized and was pretty useless without a costly rebuild
. The second had Molyslip added to the oil and, although is sounded very hollow, it kept running long enough for us to motor
about 10NM into a safe haven and, after we fixed the leak and refilled the engine with oil, the engine was used for another ten years without rebuild and without incident.