I have a chance to pick up a jon boat with a tohatsu 3.5 hp outboard on it pretty cheap. The man assured me it was running but when i tried it we couldn't get it to start. The threads on the gas tank are broke and the cap will not go on. I don't have a problem replacing the gas tank if the motor runs but i just wanted to get it started and hear it run for a second. I know it's not best to run anything without a gas cap but I just wanted to make sure it ran. Will it actually start without the gas cap? Does the gas cap help pressurize the system? Thanks to anyone who helps!!!