First go to
New Jet Ski Parts and Used Jetski Parts - Jetskiparts.com their you can look up your ski's a get a complete parts breakdown on them, and maybe help you find what your looking for.
On ski #1 , did you let this ski run for awhile in the water? Add seafoam to the gas, one can and let this ski run working some of the tarnish out of the carb as well as the old gas, this can clear up problems with the carbs, I've done this from ski's i've bought from people that have sat for years and they do clear out, worth a try other than rebuilding both of the carbs.
Ski #2, if you put this ski away running it more than likley somthing with corrosion, this I have seen also, check your stop switch. take it apart and clean it and use electrolitic grease on it, also check all your connections, this is a place to start. Also if you own 2 of these ski's go online,
DennisKirk.com - Motorcycle, Harley-Davidson, ATV, Dirt Bike, Snowmobile, PWC / Watercraft Parts, Apparel, and Accessories and buy a shop manual and it will show you with pictures how to test electrical, its just to hard to explain it to you over a chat box. Good luck.