I have just bought at an Auction a Chrysler 7.5 outboard motor for my little rubber boat. Problem I am not sure if it's 2 stroke or 4 stroke the model nember is 72H3F and the sn# 1821 I have not tried to run it as I don't wnat to mess it up. Also I have never had a outboard before so nay help would be great. Thanks in advance. Russ.