If you decide to use a Super 10 (or other green tank merc) in salty water I would suggest you can do a few thinks to minimize long term corrosion risks.
1. Take some of it apart ahead of time. Use tripple guard grease on:
water pump cover threads
pivot pin in the steering bracket
drive shaft splines under the power head
copper tube where the leg meets the lower unit
2. Run the motor in a barrel of fresh water after each use and spray it down with WD40 or some thing like that
3. I do like the idea of keeping some motors reserved for salt water use.
You'll most likely need to put a sacrificial zinc anode on it somewhere below the waterline to minimize corrosion. Flushing the motor after a trip with fresh water is necessary also. My $.02 worth is, don't do it unless it's a beater motor and you only expect one or two seasons out of it.
Good luck.
Yep, I would also recommend a good flushing and coating the lower unit screws, etc. Be careful, Kiekhaefer wasn't using stainless drive shafts during that period, so they are extra susceptible to corrosion, rust, etc. Not the best motor for a salty environment, but if that is your only option, just take the recommended precautions to minimize the effects.
