Division 4 Rules – 2021
1980 AND OLDER (this rule to be revisited annually)
4500, 5000, 5500, 6000
Any gear, speed limit 8 MPH. Speed will be checked by radar. Shifting of TA’s allowed.
If tractor is equipped with Scatter Blanket, 3/8” steel flywheel shroud, or Steel Flywheel then the following RPM rules apply:
1800 RPM 2 cylinder – 2500 RPM 4 cylinder – 3000 RPM 6 cylinder.
If tractor is NOT equipped with scatter Blanket, 3/8” steel flywheel shroud, or Steel Flywheel then 20% margin of error will be permitted.
All tractors must have positive throttle stops. Rev limiters allowed.
All tractors must be equipped with a dead man throttle.
All tractors must have fenders.
All tractors must be equipped with a kill switch and wheelie bars.
It is recommended that the tractor be equipped with a high back seat.
Steel flywheels, steel flywheel shrouds and/or scatter blankets are recommended.
Engine side shields are recommended.
Wide front ends and ladder bars are allowed.
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.
18.4 x 38 maximum allowed in all classes. Cut tire allowed. No radials or no steel wheels. Two wheel drive only. Any width rim is allowed.
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.
Frames, transmission, rear end and axle housings must be original or manufacturer’s replacement. Similar wheelbase required.
Tractors must be naturally aspirated. No turbos, blowers – except 99 GM Oliver’s, etc.
Any engine from the same manufacturer as the tractor that bolts in with the same number of cylinders and configuration is allowed. No V6 or V8 engines.
Any single updraft agriculture type carb is allowed.
Homemade or reproduction intakes and exhaust headers are allowed.
Girdles or deck plates that improve the engine rigidity and safety are allowed.
Tractor must be equipped with an operational governor.
Enhanced electrical systems are allowed.
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. Hitch material cannot be thinner than ¾” and not thicker than 1.25”. Hitch has to a 3.75” hole with 1” material thickness around the hole or a straight clevis bolted or pinned tightly to the drawbar with a minimum of 3.75” 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.
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 subject to random fuel checks. Tractors manufactured to use diesel fuel only cannot be converted to gas or LP.
REVISED FEB 2020