The old Volvo Penta MD21 engine in our Mason 43 Clover had 2500 hours on it when we bought the boat and 5500 when we had the engine rebuilt in Cyprus. Over those 3000 hours of use, we changed the crank case oil every 100 to 120 hours, changed the fuel filters every 500 hours, changed the belts every year, replaced the zincs annually and flushed the heat exchanger with muriatic acid at least every other year. We had the alternator rebuilt in Sri Lanka, the fuel pump repaired in Turkey and the raw water anti-syphon valve replaced in Malaysia. The raw water pump on that engine was its Achilles heel, which needed new impellors, shafts and keys almost annually. Through all of this, I kept the parts being replaced if they still had functionality and on numerous occasions, particularly with the raw water pump, I found myself repairing an item with pieces that had once been replaced themselves. If fact, this was a pattern aboard Clover. We carried a ton of spares for everything onboard, whether it had to do with the engine or any other piece of gear. Even when we sold the boat, we still had a dozen fuel filters, two sets of belts, a couple of years-worth of zincs and so on. We still had enough light bulbs to replace one in every lamp on the boat for years to come. We had come to realize along the many thousands of miles of cruising that being self-sufficient was not just a good idea, it was the difference between a safe and happy cruise and an unsafe and unhappy one. Redundancy is the key if you are sailing off the beaten track and off the beaten track is where we like to be.