Ok I know this might stir up trouble but thought I'd post regardless. I have a 1975 Wellcraft Airslot 24. Not special, nor rare, just a really cool old boat that rides like a Cadillac. I am leaning toward modifying (updating) the electrical system, adding convenient goodies like electronic ignition, lights, modernize control panel, and basic upholstery upgrades. If I were rich I'd drop in a 5.0 Coyote just for grins. All that said, I can just as easy... maybe easier, restore back to original and sacrifice a bit of ease of operation. Right now she's rough and needs a make over.
I think that the engine and outdrive will be your big ticket items. Maybe the outdrive needs basic servicing, maybe its toast. A safe assumption is that the motor is is toast and will need replacing. The wiring harness is anyone's guess. I would not want to rely on wire, electrical components, terminals, and connections that are 43 years old. That being said, I have started with worse.
Somewhat have to agree with sailor. Might be nothing wrong with the engine but fresh oil in the cylinders and crankcase, clean gas, freshen up the carb, check the bellows on the outdrive and of course the water impeller. Stick a garden hose up the snout and start her up. I would replace wires and connections. Once you run it you might find out that everything works fine and just needs some "fixin". The rest is all cosmetics that you can mess around with at your leisure.
Like they say from the government. "Were here to help"
Thanks, You and Sailor make good sense. I have "cleaned" the boat but still have a long way to go. I bypassed the fuel system and ran a line direct from the fuel can to the fuel pump. Engine fired right up and sounds awesome. I am taking the wiring in stages i.e. critical areas first like battery maintenance and bilge pumps. Then I will run my neg and pos mains to the terminal blocks and work out from there. The billows were replaced 4 years ago so hoping still good. The trailer needs attention so I have to address its issues before I can haul it out and give her a good servicing. But very encouraging so far! I will post pics as I wade through her.
Engine runs! That's a big deal! Like 63 sabre stated, go through all the engine systems thoroughly. be sure to use marine grade wire when replacing any wiring. I use plain crimp termials, and seal them with the shrink tubing that has the glue inside. All available on the innanet. Four year old bellows? I'd replace them just because of their age. You're going to pull the outdrive anyway, to check or replace the gimbal bearing. Sounds like you are off to a good start.