How do I know if my motor is getting enough water through the impeller? I am afraid that since it is an old motor the impellor might not work properly or might go out. How likley is this on the older evinrudes? It has always done good before, I guess I like prevenitive maintenance. Also it has an ajustment on the front of the motor for rich/lean fuel mixture but there is nothing on the inside, never has been since I had the motor. Is there somewhere I can get the little whatever it is that fits in there? Any help would be appreciated.