Have I destroyed my motor?

[DaveDomingo]

I'm a very uneducated outboard owner. I just got this manual in the hope of learning more about my mod303 (1968, 3.5 hp), and it says if I don't flush it immediately after use in salt water, really bad things happen. Same thing if I run it 'in the air' without any water coming in, "even for 5 seconds." Well, I'm confident that both things have happened repeatedly to this motor sometime over the past 46 years! I *saw* the seller run it in the air just before I bought it (to prove that it runs!!). And I, in my ignorance, have taken it out of salt water and let it sit for weeks without flushing it. How do I check for, and remedy, the kinds of damage that these behaviors are supposed to cause? Thanks, all.

 

[Frank Acampora]

The 3.5 is an air cooled engine. It does have a small water pump to cool the engine leg. If it is run in air, the impeller will be destroyed and it will no longer pump water. The leg will overheat with paint discoloration and you will get burned if you touch it.

Since no water ever touches the engine block itself, running in salt and not flushing it will not damage the basic block ( I think it is a Tecumpsa lawnmower engine). However, not flushing the leg will allow salt build-up inside the water pump and leg which can eventually lead to damage and again, lack of cooling.