I have yet to put together a kit for the Scaup, and the BBSB is sporting a new (I bought it new) Yamaha, so that kit is rather limited!
When I first started riding motorcycles, I had an old Sportster. Solid mounted motor that would metal fatigue fasteners regularly. I build up a decent kit, and spares that fit very compact. I have always had a "spares" tool box in the garage that is full of incomplete sets and less than top quality tools. I like to keep the right tool in the right place. So the table saw has the right wrenches with it, the miter saw has a 1/2" to change the blade, etc. When I worked on the Sportster, I would pull out the tool kit, even if I was working in the garage. I would use that set to do the maint, or repairs, and if I needed another tool not in the kit, I grabbed one from the box, and added it to the kit. Will start with a small ammo box for the Scaup this Summer. I just did the water pump, impeller and lower unit fluid. Plugs are delivered, but need to find the gap setting! Hope the new 40hp is reliable, especially in the cold! But if not, I hope I can find her weaknesses and work them out.....