Well, on my vintage motorbikes i never do any mechanical work until it is really needed. I just change oil and filter, but only after surpassing systematically the prescribed mileage. The less you do, the less you damage...
But an a motorbike what happens in case of failure is that you are on your feet, but there is no real risk, you do not depend on the engine for breathing.
But regulators are a different beast: when they fail, you are in trouble (also if I usually dive with two complete regulators, that's two first stages connected to two independent valves, even on a mono).
Of course I will never leave someone else than me to do anything to my vintage regulators. They are all Scubapro, four MK5 first stages, one MK15, and six 109-156 second stages (all converted to 156). I service them regularly, even if I passed some long periods without diving (up to 4 years), during which of course I did nothing to them.
Luckily enough for my regs all the parts are yet readily available, so I never had problems changing everything which did look suspect.
As others pointed out, the regs suffer if stored improperly, with salt water inside them. At the end of the diving period, when a long period of storage is planned, I substantially dismount them, and store most parts inside air-tight ziplock envelopes (those for frozen foods). At the beginning of the next season I remount them, change the parts which had some wear (seats, dynamic O-rings), apply proper lubricants and check-retune them until they are perfect.
During the season I simply wash them carefully in water at human body temperature, then I make them dry accurately removing the fist stage cap and detaching the second stage from the hose, so that air dries also the interior.
In over 1500 dives (since 1975) I had problems only twice, and in both cases it was the air filter at the entrance of first stage clogged with debris (rust, actually) coming from inside the rented steel cylinders. So one part that I change very often is the air filter, although when a lot of rust is coming from the cylinder, even a new filter will occlude easily. And this is the reason for always using two separate first stages, connected at two independent valves with independent dip pipes, and possibly on two independent cylinders.
Whatever a good maintenance is done, the real safety only comes from redundancy.
But an a motorbike what happens in case of failure is that you are on your feet, but there is no real risk, you do not depend on the engine for breathing.
But regulators are a different beast: when they fail, you are in trouble (also if I usually dive with two complete regulators, that's two first stages connected to two independent valves, even on a mono).
Of course I will never leave someone else than me to do anything to my vintage regulators. They are all Scubapro, four MK5 first stages, one MK15, and six 109-156 second stages (all converted to 156). I service them regularly, even if I passed some long periods without diving (up to 4 years), during which of course I did nothing to them.
Luckily enough for my regs all the parts are yet readily available, so I never had problems changing everything which did look suspect.
As others pointed out, the regs suffer if stored improperly, with salt water inside them. At the end of the diving period, when a long period of storage is planned, I substantially dismount them, and store most parts inside air-tight ziplock envelopes (those for frozen foods). At the beginning of the next season I remount them, change the parts which had some wear (seats, dynamic O-rings), apply proper lubricants and check-retune them until they are perfect.
During the season I simply wash them carefully in water at human body temperature, then I make them dry accurately removing the fist stage cap and detaching the second stage from the hose, so that air dries also the interior.
In over 1500 dives (since 1975) I had problems only twice, and in both cases it was the air filter at the entrance of first stage clogged with debris (rust, actually) coming from inside the rented steel cylinders. So one part that I change very often is the air filter, although when a lot of rust is coming from the cylinder, even a new filter will occlude easily. And this is the reason for always using two separate first stages, connected at two independent valves with independent dip pipes, and possibly on two independent cylinders.
Whatever a good maintenance is done, the real safety only comes from redundancy.