salt water reply
Mate.Have been looking at your thread and no answers so.
All around the pump unit there will be corrosion and the paint blistering off nozzles plates etc.If it's only surface corrosion,that's fine.But.When 2 diff. metals come together(cast alloy and stainless,bolts)you get a reaction.They can seize up,accelerate corrosion and if not properly cared for,create big problems.Sacrificial anodes should be used and replaced at about 66% gone.These corrode away instead of the ski parts.
The engine has to be religously flushed,anti-corrosion spray on after EVERY use and all moving parts sprayed as well.I have seen reverse cables,blow their plastic coating because the spiral inner cables(made of steel) rust and expand that much.This usually happens within a foot of the reverse lever..
Look for any signs of corrosion,parts that are eaten into,especially around bolts and any clicks or stiffness on throttle or reverse movements.
Hope this helps