I have my lower unit off to replace the impeller, there is sand everywhere, wuz wandering if it would hurt anything to rinse it out/off with water or will the water get in the oil or what? I havent removed the lower part to the water pump just the upper and the impeller. BTW I have a 1975 650 65horse. <br />Also the drive shaft has rust below the threads at the top and above the impeller housing, will this hurt anything or is it just dead space and nothing to worry about?