Originally Posted by Donscs
Another issue which isn’t as costly is the engine likes to make oil. Apparently when trolling for long periods of time the gas somehow gets into the oil and it gets overfilled. I can always tell when I need to check the oil and usually end up changing it when the motor starts to act a little odd when trolling, i.e., idles higher than it normally does. Not a big deal, just change it in the middle of the season.
If your making oil you have an issue you need to diagnose. Making oil can cause engine damage as oil gets contaminated.
Most common causes of making oil are a blown intake gasket or a leaking carburetor. (Injector on EFI )
You should investigate and fix this issue before it causes more issues for you.