Small Engines (Lawn Mowers, etc.): lead additive, john deere 110, dangerous chemicals

Question
I have a 1967 John Deere 110 that I use a lead additive with my gas. I just bought a new JD x304 and was wondering if I could use up the  gas or will the additive harm the new 17 hp Kawasaki? thanks  

Answer
Rob
The fuel you are using with lead will put some problems with the new mower. The new engines are made not to use lead as it will cause firing problems.Also lead in gas Lead was used in fuels as a lubricant and octane (energy level) booster.However, we have developed other less dangerous chemicals to use in it's
place in fuels.

Thanks