Motor that's sat up for years?

I have an opportunity to pick up a 75 HP Mercury the owner states has "low hours," but has not been started in 4 years. The motor is attached to an 86 Bass Tracker aluminum vhull that the owner states has seen little use for it's age. The pictures show the chrome rims on the trailer to be very rusty and the decks look like they're weathered from being outside and the carpet, seats and wooden decks need replacement according to the owner. I've posted pics over in the boats forum.

The owner's price for everything is $1000.00. I'm thinking the boat might be worth enough to take a risk on the motor, assuming some things check out like compression and lower unit oil condition.

Can you folks help me with what I should check out before buying the rig and how to find out what year motor it is? What I should consider? That kinda thing? Sorry, I'm not entirely sure of the right questions to ask on the motor.

Thank you for your help.

Bring a battery and some fresh gas for sure if you want to start it. since it's been sitting for so long,if you have a problem turning it over, take out the plugs.Then try without the plugs in to just let the starter move things around for a bit. Then if it turns over, give it fresh gas and it just may run for you. I'm not a mechanic, but that's where I'd start.

If it hasn't run in 4 years don't try to start it without first putting some 2 cycle oil down the cylinders & bring some pre mix rich in oil to shoot in the carbs.It will need a new impeller so feel the heads & don't let it get hot to the touch.Yes I would do a compression test.You didn't state what year Merc.If its an older one it could have wiring issues.Yes check lower unit oil also.

Model # should narrow down the year, serial # would nail it. If you plan to try starting it, be sure to bring a set of muffs. If you get it, should pull the trailer wheels and pack the bearings, before ya try to haul it home.