Doesn't sound like you need a new engine - you just need to clean the one you have. Back when I had an outboard
, I always had a couple of those long needles used to sew meat (turkeys and such) together before putting them in the oven
. You need to find the exit hole for the cooling
water and shove one of these needles up through it. That will clean out the salt
deposit and get the water flowing.
Then take some vinegar and rig a closed loop so the vinegar recycles through the cooling
system. Start the engine and let it run with he vinegar until the vinegar get hot. Stop and clean the exit hole again with a needles.
Your engine will probably run without any problems now. Poke a needle through on a regular basis and very year run some water with a little glycol or oil
through the engine to clean out the salt
deposits before laying it up for the winter.