The Allis Chalmers 611 Hydro is a lawn tractor produced from 1983 to 1985 as part of the 600 Lawn Series. It features an 11 hp Briggs & Stratton 399cc 1-cylinder gasoline engine, hydrostatic transmission with infinite forward and reverse speeds, and two-wheel drive with manual steering and disc brakes. The tractor was built in Port Washington, Wisconsin, USA, and originally sold for $2,499 in 1984. It has a wheelbase of 45.5 inches, weighs 550 lbs with the 36-inch mower deck, and uses lawn/turf tires sized 13-6.00x6 front and 18-8.50x8 rear. Attachments include a 36-inch mid-mount mower deck, snowblower, and blade. Electrical system is 12 volts with negative ground and 3 amps charging.