Starting a used motor after sitting for years

[djcamera]

My '86 Mercury 75hp locked up in October. So I found a guy with the identical motor for sale, but with a bad lower unit. Guy says the motor has sat for at least five years. In central Florida.

I swapped the gearcase and hung the new motor last week. Tomorrow I'll finish the wiring and I'll be ready to turn the key. I literally have no idea what's going to happen.

I tested the motor when i got it. Compression test shows 130 on all 4 cylinders (cold, with a squirt of oil). Good spark x4. It turned over nicely for the compression test. We didn't try to start it because it wasn't hooked to gas or a hose or a throttle. I figure (maybe foolishly) that if the compression and spark test good, everything else is fixable.

So...how best to be ready when I crank it for the first time? Dream scenario is it goes "VROOM" and I'm in business.

 

[maintenanceguy]

Even if it goes "vroom", I'd want to disassemble and clean the carbs before I trusted it on the water. I'd also change EVERYTHING from the fuel tank to the carbs - hoses, fuel pump, water separator, water filter, etc. Old hoses can degrade inside and tiny bits of rubber sucked into the carbs can ruin a day on the water and result in an expensive tow.

 

[1960 yellowboat]

ahhhhhhhhhhhhhhhh
mechanics LOVE Mercuries

 

[djcamera]

Even if it goes "vroom", I'd want to disassemble and clean the carbs before I trusted it on the water. I'd also change EVERYTHING from the fuel tank to the carbs - hoses, fuel pump, water separator, water filter, etc. Old hoses can degrade inside and tiny bits of rubber sucked into the carbs can ruin a day on the water and result in an expensive tow.

Good tips. Thanks.