1959 and Older


Age of Driver: Age of Driver Must Be of Age That Will Enable Them 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


Classes: 3500, 4000, 4500, 5000, 5500, 6000, 6500, 7500, 8500, 9000 #


Tires: 18.4x38 Maximum Allowed in 3500#, 4000#, 4500#, 5000#, 6000#, 6500#. 18.4x38 Maximum Allowed in  7500#, 8500#, and 9000 # Classes. Any Cut Tire Allowed. No Radials, No Steel Wheels. Two Wheel Drive Only. Any Width Rim Is Allowed.


Speed: Any Gear, Speed Limit 3.5 Mph. Speed Will Be Checked by Radar. No Shifting of Ta's.


Weights: Weights Must Not Extend Rearward beyond Rear Tires and Cannot Be More than 11 Feet from the Center of the Rear Axle to the Furthest Point Forward.


Engine: Tractor Engine Must Be Stock or Engine Must Be from Original Manufacturer and Bolt in without Modifications Using Existing Bell Housing and Motor Mounts. Frames, Transmission, Rear End and Axle Housings Must Be Original or Manufacturer's Replacement. Stock Heads and Their Replacements Are to Remain Unchanged in outside Appearance. Dual Exhaust Not Allowed except after Stock Manifold. Tractors Must Be Naturally Aspirated. No Turbos or Blowers - except 99 Gm Olivers, Etc. Replacement Carburetors with No Modifications of Carburetor or Manifold. Overhang of Carburetor to Manifold Is Not Allowed. Only Stock Appearing Manifolds Are Permitted. Enhanced Electrical Systems Permitted in All Classes. No Rev Limiters Allowed.


Rpm's: 20% Margin of Error Will Be Permitted. All Tractors Must Have Positive Throttle Stops


Draw Bars: Draw Bars Must Not Exceed 20 Inches in Height or Be Less than 18 Inches from the Center of the Rear Axle. No Part of Draw Bar May Extend Rearward beyond the Point of Hook. Draw Bars Must Be Stationary in All Directions. No Clevises.


Fuel: Gas, Diesel, or Lp Fuels Only. No Alcohol or Nitrous Oxide Fuels May Be Used in Tractors. Gas Is Allowed a Maximum of 750 Specific Gravity. All Tractors Are Subjected to Random Fuel Checks. Tractors Manufactured to Use Diesel Fuel Only Cannot Be Converted to Gas or Lp.


Other Restrictions : Oliver 88, Farmall M, Massy Harris 44, Mm-u, Jd-g, Case C/d, Jd-a 1940 and up and like Size Tractors Are Not Allowed in Classes below 4500 Pounds. Massy Harris 33, Oliver 77, Jd-a 1939 and down and like Size Tractors Are Not Allowed in Classes below 4000 Pounds.

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OSATPA Division 3 Rules