Check out this walk around of the 820 video we listed    • Walk around of the 1958  820 John Dee...  . Showing how to start a John Deere 820 cylinder that has a pony starting motor. The pony motor is a V4 gasoline engine which is started first then it is engaged to the big diesel to crank it over. Cool technology back in the day. Love this tractor but it's being sold on ebay 04/01/2013. Enjoy ebay item 330900694067