First off welcome to IDA
I’m by no means an expert, (but I do stay at holiday Inns on occasion )
I guess I start by looking everything over, does it appear he stored it properly? like stabilzed the gas and fogged it. Do you have anyway of finding out? I’d somewhat expect it to be done propely if he had the tanks filled.
I’d look into getting some fresh gas in there. First tank or two I’d highly suggest running premixed gas, watch you oil level make sure the pump seems to be pumping and using oil, before you run the motor off the oil tank. ( I believe every 2 stroke should be done like this when running it after it’s been sitting for a long period of time) Even if the gas was stabilized it’s probably no good anyways, and risky in my opinion to run it. The oil it probably alright. Try pumping up the primer bulbs, make sure they stay firm when running otherwise look into replacement.
Change the lower unit oil out, I’d probably do that befoer running it. Make sure you are getting a good flow of water out of the pee hole.
I’d also be sure and treat it for atleast the first couple tanks with a good dose of seafoam in addition to the premixed oil, and atleast one treatment of seafoam after you are done runnign premix. Get yourself an extra set of plugs.
Concerns I’d be leary of a motor not running good, don’t push it, shut it down, you could cause some major damage it’s possible the carbs got gummed up, in which case I’d consult a dealer, if you are halfway handy you should be able to clean them youself.
All that said and done, providing you check everything out well in advance, I doubt you’ll have much issue with the boat or motor, I guess this it a good start for you of where to start, I suppose some more people will be along for some more insight.
BTW Nice job on the boat Sounds like a nice one , and I see you live by my motto, “Better to ask for forgiveness than permission”