I just bought a boat with a Merc 650 65 horse outboard. I am not sure if it is a 2 cycle or 4 cycle engine. The serial number is 3403892 and I think its a 72. Came on a 72 Caravelle. I dont want to run it before I know the fuel mixture or even if the gas needs to be mixed with oil. As you can see I am new to this, but am willing to learn since I love fishing and getting out on the lake. I checked the all over the boat and cant seem the find the info anywhere. Thank you for your help.