
Lawnmower Demolition Derby Rules
A RULES FOR DEMO MOWERS – This is a WELD class
1. All of the Demo Competition & Safety Rules (1-25) apply with the following additions/exceptions:
2. Must be 14 to participate. Under 18 must have parent/guardian signed and notorized permission to participate.
3. Mower must be a factory available lawnmower or garden tractor with a maximum of 18 horsepower, 1 or 2 cylinder, vertical shaft motor. No horizontal shaft engines.
4. No rear engine mowers allowed. Engine must be factory mower engine (i.e. Briggs, Tecumseh, Kholer, etc.)
5. No frame modifications or reinforcement allowed unless specified.
6. Welding permitted using up to 1” Max welds with 3” minimum gaps. NO SOLID WELDING! You must build leg guards from foot pegs to rear fenders. This can be square tube, angle iron, or black pipe to protect your legs & feet. It must be welded or bolted & must stay in place or you will be disqualified. Shifter guard is strongly recommended to protect your hand/arm if shifter is mounted on fender.
7. You may have all thread up to ½” diameter to bolt hood to frame in no more than 2 places.
8. You may weld or bolt a small bracket to protect spark plug. This must be fastened to motor ONLY.
9. You may weld spider gears on C clip rear ends.
10. No welding or added bolting on steering, frame, or front axle. If it is a factory pivot front axle it must function.
11. Hood must stay stock & intact with the exception of replacing plastic/fiberglass hoods/panels with sheet metal but must stay same size/style as original. All mowers must run a factory hood & fenders & must have the hood either bolted or welded down to dash panel around driver area, bolts only – NO SCREWS. 3/8” size max. Max of 6 bolts (3 per side).
12. Mowers must have working brakes and forward & reverse gears at the start of heat.
13. Engine bay reinforcement is permitted with up to 1” angle iron, 3/16” thickness. May have up to 2 uprights, 2 forwards, & 1 across to fasten hood/shields to. It must be contained INSIDE hood and maintain factory body lines. Reinforcements may come in contact with but may NOT be fastened to the motor in any way.
14. Gas tank with secure cap & a max of 1 gallon of gas must be secured in the cowl or entirely below the seat. Fuel fill neck cannot stick out. Officials reserve the right to disqualify any fuel tanks they deem unsafe to run. Any gas leak & you’re done for heat.
15. A rear bumper is permitted but it is not allowed to extend more than 4” out & must stay inside the width of the inside of the rear tires. It may be no more than 1 ½” square tube or pipe & must not have any sharp edges, points, or protrusions. Bottom of bumper must not be below axle height. Halo Bar & seat protector behind seat REQUIRED & must connect to fenders or leg protection structure. Must have safety chain to hold seat from flipping up. NO SEATBELT REQUIRED!
16. Changing of pulleys is permitted & encouraged. Any & all drive train modifications are permitted but must stay belt driven. No Chain, shaft, or friction drive mowers allowed.
17. All mowers must use lawnmower type rims. Tractor treads, cut or grooved tires permitted. No tire chains, studs, duals or all steel wheels are allowed. NO valve stem protectors. Tires must be filled with air only.
18. Mower deck and all other utilities must be removed (such as tillers, loaders, or snow blowers).
19. Plastic dash & steering wheels may be left in place, but all other glass, plastic, fiberglass & trim must be removed.
20. Batteries may be left in mower if it is properly secured & covered. Must be a mower or ATV battery. Any pull start engine must be able to be restarted from the seated position with the hood closed.
21. No front bumpers allowed. Front of mower must be factory style/strait front end. Top of hood may not measure over 36”.
22. Mower must have number on each side and on top of hood. NO number tents/plates. Original style exhausts only.
23. FOR YOUR SAFETY – if a mower rolls over all participants must stop & wait until the mower is upright & driver has safely exited the arena. If your hand or foot touches the ground you are done for that heat.
24. Mower inspections will be done by designated officials only. This is still a new event and if you see something or have ideas please call, ask questions, & learn. We want to keep this an inexpensive part of the sport we can all have fun with.
25. At officials’ discretion, we reserve the right to change rules to keep the event fair & efficient. Officials’ decisions are final.
26. MOWER PAYOUTS - 1st-$200, 2nd-$100, 3rd- $50