Modified Class

AGE GROUP: 16 years or at discretion of race director

MAX ENGINE: All engines must be vertical or Horizontal crankshaft engines of lawnmower origin. OHV Engines and flat head engines in excess of 13hp (28ci) to a max of 18hp are restricted to a maximum of 3850 rpm (governed no load) strictly no modifications to these engines.

Flathead 12hp (28ci) The engines must be air cooled, no deisel engines, must run on pump gas no higher then 94 octane.

Internal engine modifications allowed using unmodified OEM parts.  Flywheels and shrouds must be stock and in good condition.  No after market or custom intake manifolds or carburetors.  Balancing and blue printing allowed, updated carburetors and valve train to OEM spec allowed.  Governors can be removed.  Custom velocity stack/air filters open.  External fuel pumps allowed. Ungoverned engines have mandatory billet aluminum flywheels.

DRIVE TRAIN: Must utilize a shiftable transmission or transaxle.  Locking of transaxle/differential allowed. Transaxle or differential can be substituted with premium keyed shaft.  Drive line pulleys, sprockets and clutch system can be modified/altered (Centrifugal clutches allowed).  Gear boxes and transaxles are not to have any gears removed.  Reverse chain can be removed for safety reasons. All chain guards must be a min thickness of 1/8″ aluminum or steel.

WHEELBASE AND MAXIMUM WIDTH: Max width 42″. Minimum wheelbase 39″

STEERING: All heim joints must be replaced with aftermarket heim joints.  Direct steering is mandatory. No plastic steering wheels unless it is the type that is reinforced with steel.

FRAME: 2″ minimum ride height.  Axle can be widened to 42″ max outside to outside of tire, mounted back underneath chassis in original OEM position, spacer brackets can be removed, no chopping of chassis to cut in rear axle.  Front axles can be modified or replaced with custom fabricated one piece beam and mounted back in original position. Slight altering of engine location allowed.

BRAKES: Aftermarket hydraulic brakes mandatory on rear only, must be on right rear axle if using an unlocked gearbox or transaxle.

WHEELS/HUBS: Steel or aluminium with hubs. 6″ front, 6″ to 8″ diameter wheels on the rear.

BUMPER/SIDE BARS: Side bars/nerf bars are mandatory, see general rules.  Cloosed loop rear bumper mandatory, see general rules.  Front bumpers optional, must be no farther than 2″ from front of tractor and no wider than the body or hood.

Note: This class will be teched or re-teched at the discretion of the Tech Steward throughout the event to enforce the RPM rule of 3650 rpm.

Min Weight:  500lbs with driver for 18hp engines, 475lbs with 16hp or less