Mercury Outboard

[WhyMe]

I recently acquired a Mercury 650 , 4 cylinder, with Single Lever, and Full gear shift and I know nothing about it. I grew up with Evinrudes and Johnsons. Where would I look to find pertinent information on the motor (serial number etc) and any other information that will help me to repair it and put it in useable condition? Any and all help will be greatly appreciated. Thanks! WhyMe