General Rules of Racing
(Apply to all classes)
1. Drivers/Membership: Every racer that competes on any night during the racing season must be a member of the lawn mower racing association. Membership fees are $25 per season and must be paid before a driver competes. Drivers must be at least 18 years old to compete in the Stock, Modified, and Outlaw Classes. Drivers aged 14 through 17 may compete in the Jr. Stock Class. However, if a driver is racing in the Jr. Stock Class and has his/her 18th birthday they may complete the year in the class.
2. Initial Tech Inspection: Before any driver competes, his/her mower must be inspected by a minimum of three designated inspectors. If the driver fails the initial tech inspection for any reason, other than safety items, he/she will have a one-race grace period. Changes must be made and approved before he/she is allowed to race on the following race night.
3. Alcohol: No driver may consume any alcohol immediately before or during any race night. Any driver that is caught consuming alcohol or that appears to be under the influence of alcohol will not be allowed to race that night. Also, there is no alcohol allowed in the pit area during or before racing. Alcohol is only allowed in the pit area after the completion of the final feature race of the night.
4. Pit Crew: The pitman must pay the same pit entry fee as the drivers and wear the same pit bracelet at any time he/she is in the pit area. A pitman is allowed to drink alcohol outside of the pit area. Any individual that is in the pit area during an event must be a minimum of 14 years old.
5. Race time: Race times will be posted and advertised before every race. All drivers must be present at the track a minimum of fifteen minutes before the calutta is scheduled to begin. Any driver missing this deadline will start all of the night’s races at the rear of the field.
6. Mower Protest Rule: Any driver may protest any other driver’s mower, in his or her own class, that is used in competition, in any night. The protesting party must file a complaint with the flagman before that class’s feature race. (I.E. if a protesting party wishes to file a complaint about the stock class they must file this before the start of the stock class’s feature race.) There will be a protest fee in the amount of $100. This protest will include the entire mower – from front bumper to the rear, however, the protesting party must point out the part, or parts, of the mower that he or she wishes to have inspected, and have a reasonable reason for the inspection of the parts. Only these parts will be viewed by inspectors. This complaint must be filed in writing (a form will be furnished) and additional parts may not be added once the form is filed. The mower will be inspected at a neutral location by a minimum of three designated tech inspectors, if three inspectors are not present at the race the entire mower will be impounded and stored at the Puk U Bar until some time when three inspectors are present. Only the tech inspectors and the owner of the mower are allowed to be present during the inspection. The mower’s owner will disassemble the mower’s engine in presence of the three inspectors. If the mower and motor is found to be illegal the complaint fee will be returned to the complaining party, the driver found using the illegal motor will forfeit any points and/or prize money earned that night, will be suspended for one race, and will be fined $25, payable before that driver can compete again. The finishing order of the races will then be scored as if that driver was not competing in that night’s events. If the mower and motor is deemed legal, the driver will receive the complaint fee, less $25 paid to the tech inspectors, and any points and/or prize money that he/she is entitled to.
7. Flags: The following flag signals will be obeyed without question:
Green: The race is underway.
Yellow: Caution, take care. No passing on the entire track. Drivers will form a single line, close up with the leader, and look to the flagman for directions.
Red: Bring mowers to a complete stop immediately.
Black: Generally for a driving or equipment violation. A furled black flag pointed at a driver is a warning to clean up his/her act. A waved black flag indicates disqualification from a race. A driver that receives the black flag must exit the track immediately.
White: One lap remaining in the event. Crossed with green flag indicates ½ way point.
Checkered: The race is over, complete the lap and pull into the pits.
8. Driver Safety Equipment: Any time that any mower is driven at speed on the racetrack drivers must be wearing the following safety items: full-face helmet, which must be D.O.T. or Snell approved, chest protector, gloves, long-sleeved shirt, over the ankle leather boots, a racing style neck brace, and eye protection, which may include goggles, a helmet face shield, or safety glasses, prescription glasses or sunglasses are not sufficient. If any driver enters the racetrack without any one of the preceding items they will be black-flagged and asked to put on the missing item. The driver will be able to start the race in their originally designated position once the missing item is put on.
9. Mower Safety and Required Equipment: All mowers must meet the following safety and equipment requirements:
1. Kill Switch: Must have a switch that turns off the ignition in the event that the mower and driver become separated. This switch must use a tether that attaches to the driver and a clip that once is removed will shut off the engine.
2. Fuel Tank: Must be securely fastened to the mower. No rubber or nylon straps, zip ties, or wire.
3. Glass: All glass articles must be removed from the mower. (Ex. Headlights, fuel filters)
4. Batteries: Must be securely fastened with a plate and a minimum of two bolts that go to the frame of the mower. Battery terminals must be covered or in a position that no shorts may occur.
5. Chain Guards: Any mower that is equipped with a chain drive must have all chains covered with a metal guard that will direct the chain downwards in the event of chain breakage.
6. Brakes: Brakes may be improved in any way and must be effective on at least two wheels. The approved testing procedure for proving effectiveness of brakes is as follows: The driver of the mower must sit on the mower and apply the brakes; the inspector will then push the mower. If the two wheels affected by the braking system slide on gravel, or the inspectors are unable to move the mower, the brakes will be deemed effective.
7. Mower Decks: Must be removed.
8. Numbers: Every mower in competition must have a dissimilar number displayed.
9. Throttle: Must have a throttle that closes the carburetor butterfly automatically when pressure is removed from the device. May be operated by either the driver’s foot or hand. Must have dual return springs on the carburetor.
10. Clutch: All mowers must have a working clutch. To prove the clutch’s effectiveness drivers must: Have the mower’s engine running and the mower moving, stop the mower, then move the mower once again, with the motor running at all times.
11. Floorboards: All mowers must have some sort of floorboard to prevent the driver’s foot from contacting the ground or becoming entangled when racing. Approval of floorboard to be determined by tech inspectors.
10. Starting Lineup: The starting lineup for each of the night’s races will be as follows:
Heat and Feature Races: General lineup will be an invert of the year’s point standings (Point leader starts in rear). However, any driver that did not compete in the previous race held, or with no points earned that year will start at the rear of the field. Drivers who missed the previous race will start in front of those with no points. If more than one driver enters a race with no points or who missed the previous race, a drawing will be held between those drivers to determine their respective starting order. Using substitute driver will be considered being present at the race, a substitute driver will start in the same position as the regular driver. A drawing will be held for the first race of the year.
B-Main: The B-Main will consist of the bottom finishers from the heat races. The top six of the Jr. Stock and Stock Class and the top four of the Modified and Outlaw Class will automatically qualify for the feature. The remaining drivers will compete in a B-Main; the top four of each B-Main will advance to the feature. If not qualified from the Heats drivers must start the B-Main to qualify for the feature.
11. Driver Points: Points will be awarded in the heat and feature races of each night of scheduled racing. The points will be awarded as follows: Heat Races: 1st – 25, 2nd – 20, 3rd – 15, 4th – 10, 5th – 5, 6th and below – 2, any driver that starts a race but does not finish will receive two points. Feature Races: 1st – 35, 2nd– 30, 3rd – 25, 4th – 20, 5th – 15, 6th – 10, 7th – 5, 8th and below – 2, any driver that starts a race but does not finish will receive two points. No points are awarded for the B-Main. A substitute driver may be used if the regular driver is unable to participate in the event, points earned by the substitute driver will be added into the regular driver’s point total.
12. Caution Flags: Any driver that is deemed to have caused a caution will be sent to the rear of the field. If a caution is called involving more than one driver and fault is not evident, both drivers involved may be sent to the rear of the field. This call is to be determined solely by the flagman and the officials; all decisions are final.
13. Cones: Any time that a cone is tipped over the caution flag will be waved, even if the cone does not enter the racing groove. The driver that caused the cone to be tipped over will be sent to the rear of the field. In the event that a competitor forces another driver into a cone the flagman will decide who is at fault and send the responsible driver to the rear.
14. Breakdowns/Accidents: If any mower breaks down or is involved in an accident and the caution flag is waved, that driver has a maximum of three caution laps, once the field is lined up in the proper starting order, to make repairs to their mower and re-join the field. Pace of the caution laps will be determined by the pace vehicle. If any mower is disabled and the driver intends to re-enter the race the mower must not be driven into the pit area, going into the pit area is a signal to the flagman that the driver is retiring from the race. Repairs must be made on the track, but off of the racing groove, within sight of the flagman. After three laps have passed, the flagman will give signal to clear the track and the mower must be taken into the pit area. Once a driver enters the pit area or re-enters the racing lineup the flagman will give the one-to-go signal and racing will resume. Drivers will be allowed to re-enter the race any time before the one-to-go signal is given. If any mower breaks down twice during one race that driver will be disqualified from that race but will be allowed to enter following races that same night.
15. Sportsmanship: Any driver contesting the flagman or officials’ decisions will be subject to the black flag and will be sent to the rear of the field. If the driver is deemed to be displaying severe unsportsmanlike conduct the flagman may disqualify the driver from the race. Any driver that is disqualified from any the race for unsportsmanlike conduct will be suspended from racing for the rest of the night and for the following two race nights, he/she will also lose all points for that racing night.
16. Rough Driving: Any driver using rough driving practices is subject to the black flag. Intentional bumping, uncontrolled ramming of the racer ahead, and blocking will not be tolerated. It is conceded that some light contact is part of racing, but any intentional infractions will result in being black flagged after one warning. If a driver is issued a warning for rough driving, the yellow flag will be shown, and the driver causing the infraction will be placed at the rear of the field. If a driver is black-flagged for rough driving he/she will be disqualified from that race and must exit the track immediately. A driver that is black-flagged for rough driving in an early race may enter a race later that night. (Ex. A driver that is black-flagged for rough driving in the heat race may enter the trophy dash and feature.)
Frame/Chassis: Must be originally manufactured for use as a lawn mower and must have the engine located in front of the driver. Zero-turning radius, rear-engine, and mid-engine mowers are not allowed. Frame must remain as originally manufactured and meet the following requirements:
1. Reinforcement: High stress areas of the frame may be reinforced to improve safety and reliability of the frame but reinforcements must not extend more than 4” along the frame. No reinforcements designed or appearing to be designed to reduce the flexibility of the frame are allowed.
2. Center of Gravity: Frame may not be modified to lower the mower’s center of gravity. The mower’s center of gravity must generally appear to be the same as originally manufactured. Height of the mower’s seat must be no less than 19” measured from the ground to the lowest point of the seat pan. (Also see “Bodywork” rule)
3. Wheelbase: Frame may not be modified so that the wheelbase of the mower is increased or decreased.
Axles: Must meet the following requirements:
1. Front Axle: The front axle used must: be an original, unmodified lawn mower front axle mounted in a position that relates to original manufacture, be welded or bolted solidly in place, not be adjustable for castor or camber, and be centered on the frame of the mower, difference in distance from mower centerline to tire sidewall on right and left side must be no greater than ½”. The spindles must be an “L” or “J” shape and must not be installed up side down so that the mower is lowered and must be approved by a tech inspector for safety. Maximum track width of the front axle is 38”, measured from the outside tire sidewall to opposite outside tire sidewall. Spindle bushing may be replaced/modified to increase durability.
2. Rear Axle: An original lawn mower transaxle must be used; gearboxes and straight axles are not allowed. The axle must appear to be mounted in a position that relates to the original manufacture of the mower. Axle must be centered on the frame of the mower, difference in distance from mower centerline to tire sidewall on right and left side must be no greater than ½”.
3. Suspension: No suspension or springs are allowed. Axles must be firmly attached to the frame and may not move independently of the frame.
Starters: Mowers must be able to start without assistance. All mowers must be equipped with either a pull or electric type starter and these must be used. Mowers with electric starters are required to have a battery that is able to start the mower’s engine mounted on the mower.
Bumpers: Bumpers and rub rails are mandatory and must be constructed of round or square tubing. Both bumpers and rub rails must be positioned so that there is a space from the ground to the bottom rail a minimum of 8” and a maximum of 10”. Bumpers must be a minimum of 6” and a maximum of 8” in height, over the entire length of the bumper. Bumpers must be no narrower than 1” inside of the outside sidewall of the tires and no wider than the outside sidewall of the tires. Rub rails may be no wider than 1” beyond a line measured from the sidewall of the front tire to the outside sidewall of the rear tire on either side of the mower. Bumpers and rub rails also must not have any square corners or sharp edges. Bumpers must also have a minimum of two crossbars attached to both top and bottom rail of the bumper. A rail along the seat to hold the driver in position during cornering may also be installed.
Wheels: Must be steel wheels a minimum of 6” in the front and 8” in the rear. May not be attached to the mower with C or E type clips, they must securely fastened with some type of pin, bolt, nut, or combination thereof. Reinforcement is highly recommended but not required.
Tires: Must use a tire that was originally manufactured for use in lawn mowing applications. All tires used must have the word “turf” molded into the tire. Maximum tire diameter must be no greater than 16”, and label must be molded into the tire sidewall.
Driveline: Pulleys may be replaced and/or modified in any way that the driver desires so long as they do not pose a safety hazard for other drivers and spectators. However, final drive ratio from the engine to the rear tires must be 13:1 or lower, racers will be periodically checked for compliance with this rule. Transaxles may be internally modified to increase the durability and performance of the unit. Reverse chains and gears may be removed. No centrifugal clutches or torque converters are allowed.
Steering: Steering system must be reinforced and may be modified in any way. Stock steering must be replaced with an approved steering mechanism, approval based on tech inspector’s discretion. All steering joints must be heim joints a minimum of 3/8”; they may not be stock ball-and-socket type joints. All bolts used in the construction of the steering must be of grade 8. Also must have a round steering wheel and the steering shaft must be located in generally the same location as originally manufactured.
Bodywork: Must use an original lawnmower hood, original lawnmower fenders, and original lawnmower body (tunnel and dash); that look generally the same as the parts originally equipped on the mower. These parts may be simply modified or reinforced to provide additional access to mechanical parts, improved appearance, or increased durability. The seat of the mower must be positioned as originally manufactured and be centered on the mower, springs and other supports for the seat may be removed so that the seat rests directly on the bodywork of the mower, but the actual body work of the mower may not be modified so that the seat rests lower than originally manufactured. Floorboards of the mower, must be mounted so that they rest no lower than the bottom of the mower’s frame.
Engine: Must be originally manufactured for use in lawn mowing equipment, be vertical shaft, factory rated at 8 horsepower or below, and have the carburetor and intake manifold originally equipped on the engine. The only modifications allowed to the entire engine are as follows:
1. Governor and all parts related to the governor may be removed.
2. Air intake before carburetor may be removed/replaced.
3. Choke plate in carburetor may be removed.
4. Exhaust muffler may be removed/replaced with an exhaust pipe. Exhaust pipe must be of a single diameter over the entire length of the pipe, no stepped pipes or mufflers.
5. Engine breathers may be modified in any way, and additional breathers may be added.
6. Engine bore may be increased a maximum of .030” to allow for rebuilt motors.
7. Head may be planed to ensure proper gasket seal, but excessive planing is not allowed. The head may not be planed enough that valve clearance is an issue.
8. Electrical charging parts may be removed from the motor and flywheel.
Any other modifications are not allowed. This includes any machine work intended to increase the performance or reliability of the engine. All internal and external parts used must be equivalents of original equipment. No modifications of original parts to improve performance or reliability of the motor are allowed. No power adders. (nitrous, turbo-chargers, etc.)
Fuel: No exotic fuels are allowed, (methanol, nitro methane, etc.) however, racers are not required to use pump gas, high-octane racing fuels are allowed.
Frame/Chassis: Must be originally manufactured for use as a lawn mower and must have the engine located in front of the driver. Zero-turning radius, rear-engine, and mid-engine mowers are not allowed. Frame must remain as originally manufactured and meet the following requirements:
1. Reinforcement: High stress areas of the frame may be reinforced to improve safety and reliability of the frame but reinforcements must not extend more than 4” along the frame. No reinforcements designed or appearing to be designed to reduce the flexibility of the frame are allowed.
2. Center of Gravity: Frame may not be modified to lower the mower’s center of gravity. The mower’s center of gravity must generally appear to be the same as originally manufactured. Height of the mower’s seat must be no less than 19” measured from the ground to the lowest point of the seat pan. (Also see “Bodywork” rule)
3. Wheelbase: Frame may not be modified so that the wheelbase of the mower is increased or decreased.
Axles: Must meet the following requirements:
1. Front axle: May be modified or completely fabricated. Front axle tube must be straight across, no angled or bent tubes. Axle may not be adjustable for castor/camber. Front spindles must be an “L” or “J” shape, must not be installed up side down so that the mower is lowered, and be centered on the frame of the mower, difference in distance from mower centerline to tire sidewall on right and left side must be no greater than ½”. Maximum track width of the front axle is 38”, measured from the outside tire sidewall to opposite outside tire sidewall. The front axle must be constructed so that the tops of the axle spindles are no higher than the bottom of axle tube.
2. Rear Axle: If a transaxle is used drivers may not make modifications to widen the unit. If a straight axle is used track width must be no greater than 38” measured outside tire sidewall to opposite outside tire sidewall. The axle must appear to be mounted in a position that relates to the original manufacture of the mower. Axle must be centered on the frame of the mower, difference in distance from mower centerline to tire sidewall on right and left side must be no greater than ½”.
3. Suspension: No suspension or springs are allowed. Axles must be firmly attached to the frame and may not move independently of the frame.
Starters: Mowers must be able to start without assistance. All mowers must be equipped with either a pull or electric type starter and these must be used. Mowers with electric starters are required to have a battery that is able to start the mower’s engine mounted on the mower.
Bumpers: Bumpers and rub rails are mandatory and must be constructed of round or square tubing. Both bumpers and rub rails must be positioned so that there is a space from the ground to the bottom rail a minimum of 8” and a maximum of 10”. Bumpers must be a minimum of 6” and a maximum of 8” in height, over the entire length of the bumper. Bumpers must be no narrower than 1” inside of the outside sidewall of the tires and no wider than the outside sidewall of the tires. Rub rails may be no wider than 1” beyond a line measured from the sidewall of the front tire to the outside sidewall of the rear tire on either side of the mower. Bumpers and rub rails also must not have any square corners or sharp edges. Bumpers must also have a minimum of two crossbars attached to both top and bottom rail of the bumper. A rail along the seat to hold the driver in position during cornering may also be installed.
Wheels: Must be steel wheels a minimum of 6” in the front and 8” in the rear. May not be attached to the mower with C or E type clips, they must securely fastened with some type of pin, bolt, nut, or combination thereof. Reinforcement is highly recommended but not required.
Tires: Must use a tire that was originally manufactured for use in lawn mowing applications. All tires used must have the word “turf” molded into the tire.
Driveline: Pulleys and sprockets may be replaced and/or modified in any way that the driver desires so long as they do not pose a safety hazard for other drivers and spectators. Must have a working lawn mower gearbox or transaxle with more than one gear. Gearboxes/transaxles may be internally and externally modified to increase the durability and performance of the unit. Reverse chains and gears may be removed. No centrifugal clutches or torque converters are allowed.
Steering: Steering system must be reinforced and may be modified in any way. Stock steering gears must be removed and replaced with an approved steering mechanism, approval based on tech inspector’s discretion. All steering joints must be heim joints a minimum of 3/8”; they may not be stock ball-and-socket type joints. All bolts used in the construction of the steering must be of grade 8. Also must have a round steering wheel and the steering shaft must be located in generally the same location as originally manufactured.
Bodywork: Must use an original lawnmower hood, original lawnmower fenders, and original lawnmower body (tunnel and dash) that look generally the same as the parts originally equipped on the mower. These parts may be simply modified or reinforced to provide additional access to mechanical parts, improved appearance, or increased durability. The seat of the mower must be positioned as originally manufactured and be centered on the mower, springs and other supports for the seat may be removed so that the seat rests directly on the bodywork of the mower, but the actual body work of the mower may not be modified so that the seat rests lower than originally manufactured. Floorboards of the mower, if equipped, must be mounted so that they rest no lower than the bottom of the mower’s frame.
Engine: Must be originally manufactured for use in lawn mowing equipment, be vertical shaft, factory rated at 8 horsepower or below, and have a lawn mower carburetor and intake manifold. The only modifications allowed to the entire engine are as follows:
1. Governor and all parts related to the governor may be removed.
2. Air intake before carburetor may be removed/replaced.
3. Choke plate in carburetor may be removed.
4. Exhaust muffler may be removed/replaced with an exhaust pipe. Exhaust pipe must be of a single diameter over the entire length of the pipe, no stepped pipes or mufflers.
5. Engine breathers may be modified in any way, and additional breathers may be added.
6. Engine bore may be increased a maximum of .030” to allow for rebuilt motors.
7. Head may be planed to ensure proper gasket seal, but excessive planing is not allowed. The head may not be planed enough that valve clearance is an issue.
8. Electrical charging parts may be removed from the motor and flywheel.
9. Flywheel key may be modified, removed, or replaced with an aftermarket key.
Any other modifications are not allowed. This includes any machine work intended to increase the performance or reliability of the engine. All internal and external parts used must be equivalents of original equipment. No modifications of original parts to improve performance or reliability of the motor are allowed. No power adders. (nitrous, turbo-chargers, etc.)
Fuel: No exotic fuels are allowed, (methanol, nitro methane, etc.) however, racers are not required to use pump gas, high-octane racing fuels are allowed.
Frame/Chassis: Must be originally manufactured for use as a lawn mower and must have the engine located in front of the driver. Zero-turning radius, rear-engine and mid-engine mowers are not allowed. All mowers must also meet the following requirements:
1. Reinforcement: Frame may be reinforced in any way so long as reinforcements do not pose a safety hazard to other drivers. Reinforcements to the frame must not be, or appear to be, a unit that would be able to function independently of the actual mower frame.
2. Center of Gravity: Frame may not be modified to lower the mower’s center of gravity. Frame height from ground measured directly behind the front axle must be no less than 6”. Frame height measured directly in front of the rear axle must be no less than 7”. Engine height from ground, measured at the bottom of the engine’s oil pan, must be 8.5” or greater. Top of the front axle tube may not be higher than the top of the mower’s frame at the point of contact with the front axle. (Also see “Bodywork” rule)
3. Wheelbase: Frame or location of axles may be modified so that the wheelbase of the mower is increased; maximum wheelbase for any mower is 50”, minimum wheelbase is 42”, measured from front axle centerline to rear axle centerline.
Axles: Must meet the following requirements:
1. Front Axle: Front axle may be modified or completely fabricated. Front axle tube must be straight across, no angled or bent tubes. Axle may not be adjustable for castor/camber. Front spindles must be an “L” or “J” shape, must not be installed up side down so that the mower is lowered, and be reinforced. Maximum track width of the front axle is 40”, measured from the outside tire sidewall to opposite outside tire sidewall. The front axle must be constructed so that the tops of the axle spindles are no higher than the bottom of axle tube. Offset is allowed.
2. Rear Axle: Maximum track width of the rear axle is 40”, measured from outside tire sidewall to opposite outside tire sidewall. Track width may be obtained by modifying a stock transaxle or installing a straight axle. Offset is allowed. The rear axle must be installed so that the top of the axle is no higher than the bottom of the mower’s frame. (I.E. the mower’s frame may not be notched so that the axle is tucked up into the frame, lowering the mower.)
3. Suspension: No suspension or springs are allowed. Axles must be firmly attached to the frame and may not move independently of the frame.
Bumpers: Bumpers and rub rails are mandatory and must be constructed of round or square tubing. Both bumpers and rub rails must be positioned so that there is a space from the ground to the bottom rail a minimum of 6” and a maximum of 8”. Bumpers must be a minimum of 6” and a maximum of 8” in height, over the entire length of the bumper. Bumpers must be no narrower than 1” inside of the outside sidewall of the tires and no wider than the outside of the sidewall of the tires. Rub rails may be no wider than 1” beyond a line measured from the sidewall of the front tire to the sidewall of the rear tire on either side of the mower. Bumpers and rub rails also must not have any square corners or sharp edges. Bumpers must also have a minimum of two crossbars attached to both top and bottom rail of the bumper. A rail along the seat to hold the driver in position during cornering may also be installed.
Starters: All mowers in the must be able to start without assistance. All mowers must be equipped with either a pull or electric type starter and these must be used. Mowers with electric starters are required to have a battery that is able to start the mower’s engine mounted on the mower.
Tires: Must use a tire that was originally manufactured for use in lawn mowing applications. All tires must have the word “turf” molded into the tire.
Wheels: Must be steel wheels a minimum of 6” in the front and 8” in the rear. May not be attached to the mower with C or E type clips; must securely fastened with some type of pin, bolt, nut, or combination thereof. Reinforcement of wheels is highly recommended but not required.
Driveline: Pulleys and sprockets may be replaced and/or modified in any way that the driver desires so long as they do not pose a safety hazard for other drivers and spectators. Must have a working lawn mower gearbox or transaxle with more than one gear. Gearboxes/transaxles may be internally and externally modified to increase the durability and performance of the unit. Reverse chains and gears may be removed. No centrifugal clutches or torque converters are allowed.
Steering: Steering system must be reinforced and may be modified in any way. Stock steering gears must be removed and replaced with an approved steering mechanism, approval based on tech inspector’s discretion. All steering joints must be heim joints a minimum of 3/8”; they may not be stock ball-and-socket type joints. All bolts used in the construction of the steering must be of grade 8. Also must have a round steering wheel. Steering shaft must be located in generally the same location as originally manufactured.
Bodywork: Must use an original lawnmower hood, original lawnmower fenders, and original lawnmower body (tunnel and dash); these parts may be modified or reinforced to provide additional access to mechanical parts, improved appearance, increased durability, etc. The seat of the mower must be centered on the mower, springs and other supports for the seat may be removed so that the seat rests directly on the bodywork of the mower, the actual body work of the mower also may be modified so that the seat is lower than originally manufactured, although the bottom of the seat pan may not rest lower than the top of the rear tires.
Engine: Must be originally manufactured for use in lawn mowing equipment, be vertical shaft, be 31 cu. in. or smaller as delivered from the factory, have only one cylinder, and have lawn mower carburetor and intake. The only modifications allowed to the entire engine are as follows:
1. Governor and all parts related to the governor may be removed.
2. Air intake before carburetor may be removed/replaced.
3. Exhaust muffler may be removed/replaced with an exhaust pipe.
4. Engine breathers may be modified in any way, and if desired, additional breathers may be added.
5. Engine bore may be increased a maximum of .030” to allow for rebuilt motors.
6. Head may be planed to ensure proper gasket seal, but excessive planing is not allowed. The head may not be planed enough that valve clearance is an issue.
7. Compression release lobe may be machined off of the camshaft, but no other modifications may be made to the camshaft.
8. Choke plate may be removed from the carburetor.
9. Valve retainers may be upgraded. Must use stock valves, springs, and rocker arms.
10. Jetting in the carburetor may be changed; an adjustable jet may be installed.
11. Mowers must be equipped with a stock flywheel. The flywheel may not be modified so that it is lighter that originally manufactured, however, the interior magnets, and the starter ring may be removed from the flywheel. Flywheel must be the size and type that was originally equipped on the motor used. No aluminum flywheels.
12. Internal “syncro” balance of the engine may be removed and replaced with aftermarket counterweights. OEM crankshaft and connecting rods must be used.
Any other engine modifications are not allowed, this includes the motor’s carburetor and camshaft. Only the modifications previously listed are allowed. All internal and external parts used must be original equipment or equivalents of such. No modifications of original parts, other than modifications listed above, to improve performance or reliability of the motor are allowed. No power adders. (nitrous, turbo-chargers, etc.)
Fuel: No exotic fuels are allowed, (methanol, nitro methane, etc.) however, racers are not required to use pump gas, high-octane racing fuels are allowed.
Frame/Chassis: Any type of frame/chassis is allowed. Drivers may use an original lawn mower frame or fabricate the entire frame. Engine must rest in front of the driver. Bottom of the frame at all points must be a minimum of 4” from the ground. Wheelbase of the mower may be a maximum of 50”, measured from front axle centerline to rear axle centerline. Mowers may be equipped with a roll cage, but roll cages are not required. If a mower is equipped with a roll cage it must also be equipped with a racing style high-back seat and a five-point racing harness.
Axles: Must meet the following requirements:
1. Front Axle: Front axle may be modified or completely fabricated. Maximum track width of the front axle is 40”, measured from the outside tire sidewall to opposite outside tire sidewall. Offset is allowed.
2. Rear Axle: Maximum track width of the rear axle is 40”, measured from outside tire sidewall to opposite outside tire sidewall, any type of axle is allowed. Offset is allowed.
3. Suspension: No suspension or springs are allowed. Axles must be firmly attached to the frame and may not move independently of the frame.
Bumpers: Bumpers and rub rails are mandatory and must be constructed of round or square tubing. Both bumpers and rub rails must be a minimum of 3” and a maximum of 5” from the ground to the bottom rail. Bumpers must be a minimum of 6” and a maximum of 8” in height, over the entire length of the bumper. Bumpers must be no narrower than 1” inside of the outside sidewall of the tires and no wider than the sidewall of the tires. Rub rails may be no wider than 1” beyond a line measured from the sidewall of the front tire to the sidewall of the rear tire on either side of the mower. Bumpers must also have a minimum of two crossbars attached to both top and bottom rail of the bumper. Bumpers and rub rails also must not have any square corners or sharp edges.
Tires: All tires used must either have the word “turf” molded into the tire, or be specifically approved by a minimum of three members of the rules committee. Any type of performance compound or competition kart tire is not allowed. If a driver has any doubt of the legality of a certain tire it is highly recommended that the tires are approved before purchase.
Wheels: Open to any size/type that is desired Wheels may not be attached to the mower with C or E type clips; they must be securely fastened with some type of pin, bolt, nut, or combination thereof. Reinforcement of wheels is highly recommended but not required.
Driveline: Drivers may use any driveline desired.
Steering: Steering system must be reinforced and may be modified in any way. Stock steering gears must be removed and replaced with an approved steering mechanism, approval based on tech inspector’s discretion. All steering joints must be heim joints; they may not be stock ball-and-socket type joints. All bolts used in the construction of the steering must be of grade 8. Also must have a round or butterfly style steering wheel.
Starters: Mowers must be able to start without assistance. All mowers must be equipped with either a pull or electric type starter and these must be used. Mowers are not required to have a battery mounted on the mower.
Bodywork: Must use an original lawnmower hood, original lawnmower fenders, these parts may be modified or reinforced in any way to provide additional access to mechanical parts, improved appearance, increased durability, etc.
Engine: Must be originally manufactured for use in lawn mowing equipment, be vertical shaft, and must have a lawn mower carburetor. Any internal or external modifications are allowed. A stock flywheel is not required, but if one is used it may not be modified so that it is lighter that originally manufactured, however, the interior magnets, and the starter ring may be removed from the stock flywheel. No power adders. (nitrous, turbo-chargers, etc.)
Fuel: No exotic fuels are allowed, (methanol, nitro methane, etc.) however, racers are not required to use pump gas, high-octane racing fuels are allowed.
