It is easily the most complicated, highest design-quality ride-on I've ever seen, but that makes it difficult and expensive to maintain, like a car. However it should last like a car too, if you maintain it like one.

Incidentally I've seen what seem to be two separate reports on the internet of mice or rats making a nest inside the flywheel of that machine (back of engine, where the propeller shaft attaches). In both cases the rodent fared poorly when the engine started, because of the toothed belt drive for the camshaft, which is adjacent to the hollow side of the flywheel. Poor little guys went between the belt and the toothed pulley. If you've got a mouse infestation in your flywheel too, you need to attend to it. You may need to pull the flywheel to clean out its interior. It is drilled for a three-hole flat plate puller, and that is the right way to take it off. The starter ring gear is machined into the exterior of the cast iron flywheel, and if you try to use a gear puller there's a good chance you'll break off some teeth.

While you are there, be sure and check the tension on the toothed belt. If it is allowed to get slack it will jump teeth, and you'll have to pull it apart again to replace it. You adjust the tension by sliding the water pump outward:
[Linked Image]
[Linked Image]

Note that the water pump seems to be held by four bolts, one of which has to be approached from the back of the water pump (that is the one furthest to the right). If the belt is slack it is sure to be worn, and it would be best to replace it rather than go through the whole process again when it wears a bit more and jumps its timing.