Can you use uleaded gas in your ted Williams 4.5 hp outboard when it says to use leaded?

Your engine says to use leaded gas in it because when it was made, leaded gas was what you got. The lead was there to protect the valves in a four-stroke engine. A two-stroke like yours has no valves, so it needs no lead. Ipso facto, so long as you keep putting a good grade of two-stroke oil in your gas, you can run all the unleaded in it you want.