I just picked up a Yamaha 6 HP from a Pawn shop today and I would like to know what year model it is, the model is 6SG. Overall it looks to be in great condition, the outside has a few scratches here and there and the prop has a few small dings. Under the top cover it looks Brand New. It also came with a nice Yamaha tank, When I got home I noticed a funny smell like the fuel has been sitting in the tank for a while, also It looked a little rusty in the tank. I am now worried that the pawn shop might have tried to start the thing with this old rusty fuel!! They gave me a 30 day return on this motor if it does not run, so I would like to test out ASAP, but I'M worried about this rust, should I clean the tank up good and give it a try? Or should I also try to clean the Carb out just in case they tried to pump rusty fuel thru it. Also how long does it take for the fuel in a tank to get foul like this? And what is the best Way to clean this old fuel and rust out so that it will not affect the motor. Also it says on the motor to run at 100:1 mix, does yamaha make a special mix for this motor that I should use? I paid $175.00 for the motor so if it runs I think I got a good deal. Thanks for any help you can give this novice.