I have looked and looked for the serial number on my tohatsu, but I think the numbers are missing. Is there any other way to tell what year it is. It is dark blue, with a gray/silver top. There are a dark blue as well as a lighter blue accent line on the top as well. It is a 40 hp with elec. start. Also can someone tell me how to change out the impellor. How do i detatch the shift rod from the lower unit so I can take the lower unit off? I know I sound really stupid but thanks for any help.