There's a lot to go over if this boat is new to you. You should check out all subsystems. Do not rely on someone else's experience. For instance, I don't see a definitive comment, is the VRO bypassed for certain or are we just talking? If the VRO is working then do not premix your fuel. You'll run too rich, no? Are we commenting because you think you have a VRO problem?
Put a timing light on each cylinder. Easy test.
Lower unit should get an oil change and check (seals) for water.
Water pump impeller should be new-to-you. Do not gamble. Change it and the associated grommets, get a drive key too just in case you lose the old one.
Is the thermostat working properly? Watch running temp with an infrared thermometer.
Change your spark plugs. They're cheap.
Get on line and watch a few videos. Everything is out there. From how to start to how to rebuild. It's all there.
Get a hardcopy book, remember those, on repairing outboards, generic, cheap.
J
