The number you gave is the serial number. If it’s a single cylinder, water cooled motor,
you probably have the 1940 model 571.40
1940 HP Cyl’s
571.33 AC8001 – AC11565 Air Cooled .75 1 Made by Kissel
571.34 DAC25001 – DAC28905 Air Cooled .75 1 Made by Kissel
571.34A DAC25001 – DAC28905 Air Cooled .75 1 Made by Kissel
571.40 S50001 – S56103 Water Cooled 2.75 1 Made by Kissel
571.12 S37001 – S44106 Water Cooled 3.5 1 Made by Kissel
571.23 T18001 – T23003 Opposed Twin 5.75 2 Made by Kissel
550.75 (5810) Opposed Twin 8.5 2 Made by Johnson Mod