I recently purchased a 1973 Mercury 1150 from my nephew. There was no owner's manual and he wasn't sure of the fuel oil mixture ratio. The tank is about half full of very old gas. I want to replace the old gas but I'm not sure of the correct mixture. The Serial Number of the engine is 3754296. I would like to buy an owner's manual but have only found repair manuals on the internet. Any suggestions?
