How long can a small outboard motor be submerged in fresh water before it's not salvageable?

Over the weekend we recovered a HONDA outboard motor that fell off a fishing boat last September. It's since been power washed and the carburetor has been removed along with all internal water. Is it worth taking to a repair shop?

No

Remove the plug and hand crank it repeatedly until there's no more water coming out of the chamber. Purge all the fuel lines and the fuel tank. If it is a 4 stroke, change the oil. Spray starting fluid on the chamber and put a new plug. Try to start. If it starts and dies, reinstall the carb (after cleaning it), put fresh gas and try to start again. If it will not tstart with the starting fluid, check for spark. Ignition coil could be toast.

Unlikely. The cylinder bore wil be pitted by corrosion as will any other ferrous parts such as bearings. Maybe it can be rebored and an oversize piston fitted. You will just have to examine every component carefully.

If it was in fresh water, there should be no problem with internal corrosion. If the motor was NOT running when it fell in, there should be no damage. Just drain all the water out of the crankcase and lower unit, refill with fresh gas and oil and it should be good to go.

We have no way to know that.

You have a nice Scrape metal anchor now!

Probably not it would at least be a grand to repair

How long it has been submerged isn't as important as how long it's been up. As soon as air hits it it starts to rust. In order to save one it needs to be 'fogged' and started as SOON as possible. You will have electrical problems too.