I often tell people If you are going to own a 20+ yo high performance 2 stroke anything you will need some mechanical skills and develops more. Wether that is a jet boat, jet ski, snowmobile or other it will require virtually constant upkeep. The nature of these performance engines running close to optimal all the time. That said it is very doable for those with desire and some skills and the ability to learn.
The huge bonus is sites like this and the fact that nearly all of the issues you will have are answered. I keep a 3-ring binder with all sort of specific notes about my 1997 Challenger 1800. Print out threads and highlight issues and solutions so when they come back the answer is there. Also when you solve something that you asked about here, PLEASE come back and post a follow up. It helps everyone.
Last weekend I did the set of carbs on the starboard engine in my boat. About 3.5 hours between grabbing first tools to pushing starter button to check if I did it right. Not my first time doing a set of 787 carbs. I’m guessing the first time it was close to twice as long. Just follow the steps that
@mikidymac so kindly laid out.
If you don’t want to wrench on a boat then a mercruiser 3L maybe better suited. Here in the northeast there aren’t many/any marinas that will work on these 25 year old boats.