Age of driver: Age of driver MUST be 16 years of age or older and  able to operate the tractor in a safe and proper manner. Those under 18 years of age MUST have a parent/guardian signed insurance waiver, good for the season, on file with OSATPA

No year limit on age of tractor.

Classes: all classes 8500# - 4 MPH, 6 MPH, 8 MPH, and 10 MPH (2016)

Tires: 18.4 x 38 maximum allowed in all classes. Radials allowed. CUT TIRES ALLOWED.

Speed: Speed limit - 8500# 6 MPH, 8500# 8 MPH, 8500# OPEN 4 MPH. Mandatory wheelie barsand kill switches. Scatter blankets and steel flywheels not required but recommended.

Fuel: Diesel only.

RPM's: Maximum 3000. The governor lever must come to the governor stop on all injector pumps.



Hitch material cannot be thinner than ¾” and not thicker than 1.25”. Hitch has to a 3.250” hole with 1” material thickness around the hole or a straight clevis bolted or pinned tightly to the drawbar with a minimum of 3.250” hole. Top of hitch adjuster cannot be above center line of axle or hub. Hitches and drawbars must be stationary in all directions. Hitches or drawbars cannot be moved when pulling down the track.

Cylinder Block or Crane Case, Heads: Tractors must have a stock engine, stock cylinder heads, and their replacements are to remain unchanged in outside appearance. Engine cubic inch must be stock or manufacturer replacement.

Hood, Grill, Frame, Transmission, Rear End, Axle: Must be for that make and model and must maintain stock appearance and dimension.

Total Length of Tractor: Maximum is 12 feet from the center of the rear axle to the furtherest point forward, including weights. Weight brackets may be used.

Manifolds, Injector Pumps: All manifolds must be from the same manufacturer and must bolt in stock location without modification. Manifolds may be altered to fit turbo under hood. M&W OK. Any rotary injection or Sims pumps, or Standine replacement. A pumps allowed.


This site is owned and maintained by OSATPA.  2013.

OSATPA Division AFS (Altered Farm Stock) Rules