1.        Modified tractors are those using any combination of engine(s), transmission(s), and final drive.

 2.        No portion of tractor may exceed 14’ forward of the center of the rear wheel.

 3.        Chassis – Modified tractors that have the frame bolted to the transmission shall also have the frame bolted to the axle housing to prevent splitting of tractor. The frame must be of sufficient strength that even when the bolts from the plate of the transmission or rear end are removed, the frame still supports the weight of the tractor in the heaviest class being entered.

 4.        Driveline/Driveline shielding:

a.  No shaft over 48” long allowed. No input or output shaft that attaches to drive shaft may extend more than 4” beyond a bearing.

b. A minimum of 1” material between bolt and end of drive shaft shield. A minimum of 1” material to be in pilot holder at each end of the drive shaft shield. A minimum of eight (8) 3/8” (grade #8) bolts to hold carrier-bearing assembly if attached to a vertical plate.

 5.        Tires:

a.  Tires no more than 30.5” wide.

b. Rim diameter limited to 32” on tire widths over 24.5”.  Note: Width determined by manufacturer’s size.

 6.        Engine Limit:

a.  Naturally aspirated automotive engines (must be carbureted) up to three engines, not to exceed 2000 cubic inches collectively.

b. No more than two (2) pressurized automotive engines (blowers, turbos, or fuel injected) No cubic inch limit.

c.  Turbine limit – 1 at 2300 H.P.; 2 at 1300 H.P. government rating.

d. Other – Truck, aircraft (diesel or Allison) pressurized limit one (1).

 7.        Modified Open Class: Northwest rules for Modified tractors apply. Pro-Stock, Super Stock, Mod-Stock can enter but must meet Northwest rules. Farm Stock can enter but must meet Northwest rules.

1.        Weight Class: - 6200 and 7200 lbs. classes.

2.        Engine Limit:

a.  Automotive -type cast iron block.

b. Cast iron or aluminum heads. One (1) spark plug per cylinder.  Two (2) valves per cylinder.

c.  Eight (8) cylinder maximum.

d. Any intakes allowed.

e.  Two (2) four-barrel carburetors maximum or fuel injection.  Naturally aspirated; no blowers.

f.   540 cubic inch.

g. Spark plug shielding - must cover the plugs to deflect plugs with a minimum of .060 metal.

1.        Weight classes are 6000, 6600, and 7500 pounds.

 2.        All weights must be securely fastened to tractor.  No weights permitted on seat or deck, any weights or external parts lost while hooked to the sled while under green flag will be cause for disqualification of the pull.

 3.        All tractors must be equipped with both rear brakes working.

 4.        Modified stock classes are open to naturally aspirated engine only.  Tractors must have rubber tires, no dual wheels, studs, or chains with all power being transmitted through rear wheels.  Cut tires are permitted.  All four wheels must be in place but not necessarily in factory position.

 5.        No R.P.M. limit.

 6.        Tractor motor, transmission and rear end must conform to each other and must be in the stock location.  Block and cylinder head must be O.E.M for make and model of tractor.

 7.        Clutch housing, transmission case, rear end housing, and axle housing must be O.E.M for make and model of tractor.

 8.        Minimum drawbar length is 18 inches from the center of rear axle to hook point.  Drawbar must be stationary in all directions.  Maximum height is 20 inches from top of hitching device parallel to the ground.  Any vertical clevis will be measured to center of loop.  No bracing above center of rear axle.

 9.        Drawbar must be equipped with steel hitching device with thickness no less than 1-inch square or 1-1/8 inch round stock and no more than 1-1/2 inch square or round stock.  A 3-inch wide by  3-1/2 inch long hole is required.  A cross-sectional thickness of 1 square inch minimum must be maintained at any given point of hitch loop.

 10.     Tire size will be 18.4 x 38 inches maximum.

 11.     Diesel can use any fuel system.  Gasoline powered tractors must use only one updraft carburetor.  Tractors must use fuel that engine was designed for.  No alcohol fuel allowed.  Electric fuel pumps are permitted.  Engine must use O.E.M manifolds.  No fuel injection of any type, except for diesel engines.  Carburetor flange will be no more than 1 inch from stock length.  No water injection.  No overhead cams.  All propane tractors should have only one regulator.

 12.     All tractors must have all safety equipment, (I.E. side shields from top of block extend 2 inches below center throw of crankshaft, must be 1/8 inch steel or aluminum).  Must have fenders, kill switch and return spring on throttle plate.

 13.     Maximum length from center of rear wheel to forward most portion of tractor is 13 feet.  Maximum wheelbase is not to exceed 114 inches.

 14.     Officials may order driver/owner to remove shields for inspection.  The driver/owner will be present at inspection.  A closed inspection will be honored.

 15.     Power shift and clutch update are okay, if no modifications are made to chassis.  Any tractor in question of being legal will be ruled on by the rules committee and board of directors.

 16.     Full-face helmets, fire suits and leather shoes are required.

 17.     Cubic inch limit for all makes and models is 680 cubic inches.  All tractors over 680 cubic inches must run with an R.P.M. limit.  R.P.M.’s allowed will be 130% of manufacturer’s data of that series engine.  Tractors over 680 cubic inches also should run under N.A.T.P.A. (National Antique Tractor Pullers Association) rules – Division V.

 18.     A protest rule will be in place for these classes.  A fee (tear down money) of $500.00 cash must be posted by the protestor(s) at the event.  The burden of proof of the legality of the tractor in question is placed on the vehicle’s owner.

 19.     Wheelie bar specifications:

a.        Maximum height from ground 10 inches.

b.       Maximum length 32 inches from center of axle to back of wheelie bar.

c.        5-inch square plate on bottom of wheelie bar.

d.       Must not be attached to the hitching devices.

e.        A random check can be made where the tractor is jacked up using the wheelie bar.  The wheelie bar must hold the weight of the class the tractor is pulling.

 20.     Non-cast flywheels are required.  Must have a 3/8” plate around the whole bell housing or a 5 strap blanket required. Any steel shrouding must be fastened by 3/8” grade 5 bolts and nuts or better with a maximum spacing of 6” inches.

 21.     A maximum 1 ½” spacer between the intake manifold and the head will be permitted.

 22.     Special Exceptions:  Allis Chalmers D19 tractors may move the intake flange 2” toward the center.

 23.     Non-cast structure steel or aluminum from back axle housing to front frame that will support the tractor is required.

 24.     The Board of Directors and Rules Committee reserves the right to change a rule if deemed necessary for a safety issue during the pulling season and for changes for 2009 season such as a handicap system, weight allowance, etc.