COMMON SPECIFICATIONS FOR ALL PREPARED CLASSES:
PREPARED CLASSES: Class designation: GPK, GPS, GPT, CP and BP.
Mowers must remain as delivered from the factory except for the modifications listed below. All parts should be of lawnmower origin with the exception of those specifically mentioned below.
ENGINE:
-Must be originally manufactured for use in lawn mowing equipment and be stock in appearance with the exception of the air filter, air cleaner or velocity stack. (GPK, GPS, & GPT must have stock air filter assembly and filter).
-Crankshaft must be in original orientation and clearance hole in the frame.
-Engine may be internally modified in CP & BP
-In every class the original engine block assemblies must be used. For example: cylinder block, sumps, side covers and cylinder heads. The only exception is the valve cover. Billet/aftermarket valve covers can be used to allow clearance for roller rockers if used. Billet side covers and sumps or forged aftermarket cylinder heads are illegal.

-External ignition systems ARE allowed in CP and BP

CHASSIS:
-The mower must be a full-size lawn mower

-Front Engine Frame

-Mid-engine frames are NOT allowed.
-All parts must be of lawnmower origin with the exception of those specifically mentioned herein or otherwise allowed in class specifications

DECKS:
-Mowers may mount steel factory decks or Simulated Decks.

-The deck must be at least as wide as either running boards or body edge, whichever is wider.
-Decks may not extend any more than 2" beyond the tire sidewalls on each side.
-Deck halves may be mounted to running boards.

-Decks must be secure.

WHEELBASE:
-Width is a maximum of 40" sidewall to sidewall.

WHEELS:
-NO factory lawn mower wheels
-Wheels must be the same size on each axle, of any origin, made of metal. -No dual or tandem wheels.

REAR AXLE:
-Rear wheels are secured with lock collars.
-C-clips are NOT allowed.
-Front spindles use either lock collars or castle nuts with cotter pins. Lock nuts are no longer sufficient.
-Rear axle may use open differential, locked, “live” or solid axle.
-No single wheel drive.
-Must use axle mounted brakes.
-No lawnmower transaxle or transmission mounted brakes are allowed.

DRIVELINE:
-May be modified from the engine pulley to the rear wheels, but must utilize a shiftable lawnmower transmission or transaxle.
-No vari-drives, centrifugal and or torque converter clutches.
-Design is open, but must terminate away from the driver and competitors, in a rearward and/or downward direction and present no apparent safety hazard.

THROTTLE:
-Mowers must be equipped with an automatic throttle-closing device.
-Hand throttles that are adjustable must be disabled so they cannot be adjusted or moved by the driver at any time during competition. This is for Governed Classes ONLY.

-Cables must be secured so that the engine’s RPM’s cannot be affected by moving the cable in any way, or at any time.

KILL SWITCH:
-Mowers must be equipped with a kill switch, which will turn off the ignition if the driver leaves the mower.
-Velcro is NOT acceptable.
-Pressure switches are NOT allowed.
-The kill switch must remain in a closed position (engine not running) until driver mounts the mower.

-Additional switches that by-pass the kill switch are NOT allowed under any circumstance.
-Homemade kill switches are NOT allowed.

BODY:
-Must be stock, without external alterations, although discrete strengthening is allowed. -Hood must be secured.
-Hood must be hinged or have a hole in the grill for access to spark plug wire for required “RPM” checks.
-Minimum 4" ground clearance to frame, and 2-1/2" from ground to the bottom of deck.

-Footholds must be discrete, and no more than 2" high, made of flat or “L” stock (no rod stock), and made such that the foot cannot become entangled in a rollover.
-Rear bumpers are strongly recommended (NO SQUARE TUBING OR SHARP EDGES)
-Actual lawnmower seats must be used.
-Bottom of seat to the ground must be a minimum of 13 inches.
-Fenders may be discretely moved and altered

GPK, GPS and GPT CLASS:

SPECIAL REQUIREMENTS:
GPK is ages 9-15 years old
GPS & GPT is ages 16 and Up.
-Parents/legal guardian must be present on race day.
-Parents/legal guardian must be available to work corners or in the infield if needed during GPK races.

*All Governed Class mowers are required to stay on the track and kept running at the finish line after the FEATURE RACE for RPM check. Leaving the track or shutting off the engine will result in disqualification. Please go over this procedure with your child before race day.

ENGINE:
-Governed at 3,650 RPM maximum with no load (foot off the clutch in Neutral).

GP & GPK
-33ci Maximum Single-cylinder, overhead valve engines or L-head (flathead) must be stock, complete, and not exceed the factory rating.

GPT
-49 ci Maximum Twin-cylinder, overhead valve engines must be stock, complete, and not exceed a factory rating of 810cc 49cu in. No Big Block Engines.

-Must have stock air filter assembly and filter.
-After market consumable parts such as air filters and spark plugs may be used as long as they are a direct stock replacement.
-Mower MUST have original stock flywheel.

WHEELBASE:
-Center of the front axle to the center of the back axle is a 42" minimum unaltered wheelbase.

WHEELS:
-6" minimum front wheels and 6” minimum rear wheels.

CP CLASS:

Special exception: 15 year olds may race CP with 2+ years lawn mower racing experience (MUST BE CLEARED BY STAFF)

ENGINE:
-All single-cylinder overhead valve and two-cylinder valve in block, 4 stroke engines. -Mid-engine frames are not allowed.
-Aluminum flywheels are MANDATORY

WHEELBASE:
-Center of the front axle to the center of the back axle is a 42" minimum unaltered

wheelbase.

WHEELS:
-6" minimum front wheels and 6” minimum rear wheels.

BP CLASS:

ENGINE:
-All overhead valve V-twin, 4 stroke engines, 810cc 49 cu in and under, No Big Block Engines.
-Mid-engine frames are not allowed.
-Aluminum flywheels are MANDATORY

WHEELBASE:
-Center of the front axle to the center of the back axle is a 42" minimum unaltered wheelbase.

WHEELS:
-6" minimum front wheels and 6” minimum rear wheels.

I-MOW & JP CLASSES:

JUNIOR PREPARED CLASS (for Ages 7-15)

I-MOW (Adult)

A highly regulated class to ensure uniformity between JP machines. The intent is to have the mowers be as identical as possible so JP kids can gain experience & develop the skills to advance to a “Prepared Class” when they come of age. These machines are essentially a Prepared Chassis

-Parents/legal guardian must be present on race day

-Parents/legal guardian must be available to work corners or in the infield if needed during JP races.

*All Governed Class mowers are required to stay on the track and kept running at the finish line after the FEATURE RACE for RPM check. Leaving the track or shutting off the engine will result in disqualification. Please go over this procedure with your child before race day.

ENGINE:

-Governed at 3,650 RPM maximum with no load (foot off clutch in neural).

-Single-cylinder, overhead valve engines or L-head (flathead) must be stock, complete, and not to exceed a factory rating of Box Stock Legal.

-After market consumable parts such as air filters and spark plugs may be used as long as they are a direct stock replacement.

-Mower MUST have original stock flywheel.

WHEELBASE:

-Center of the front axle to the center of the back axle is a minimum 39" unaltered.

WHEELS:

-Metal rims: 5" minimum front wheels; 8" minimum rear wheels.

-Rear tires are a maximum of 16" diameter as written on the sidewall of the tire.

-Actual diameter may not exceed 16-1/4”.

-Maximum 15 PSI tire pressure.

-Wheels must be the same size on each axle, of any origin, made of metal.

-No dual or tandem wheels.

DRIVELINE:

-Transmission or transaxle must be shiftable and of lawnmower origin and gear ratio in highest gear can be no less than 8:1. Example: While in the highest gear, the rear wheels can turn no more than one revolution every time the engine rotates eight (8) times. Driveline may be modified from the engine pulley to the rear wheels, but must utilize a shiftable lawnmower transmission or transaxle. No vari-drives, centrifugal or torque converter clutches. Mowers using a chain drive type transmission must use an axle- mounted brake system. 

AP/MINI PRO CLASSES:

ENGINE:

-4 stroke engines, 10.5hp and below with a factory maximum stock original displacement of 22ci, (both valve-in-block, L-Head and overhead valve)

-May use Honda GX 200 or 196cc clone engine

-Must use pull start

-Crankshaft must be in original orientation.

-Engine plate may be welded to frame rails in as close to the original location as possible.

-Aluminum flywheels are MANDATORY.

WHEELBASE:

-Center of the front axle to the center of the back axle is a 34" minimum unaltered wheelbase.

WHEELS: 

-4" minimum front wheels and 6" minimum rear wheels. 

-May use turf tires, racing tires, or go kart slicks