05/15/2026
Martin County Backyard Rules Package 2026
*Effective 5/23/26 - there have been changes made to Sport Stock rules and payout from the protest.*
Age group classes:
Tater Tot: Up to 7 years old
Kids: Up to 12 years old
Junior: Up to 16 years old
If a racer is capable above and beyond their age group it is up to the tracks discretion to ask them to graduate to the next class.
Tater Tots:
Box stock motors and to be maintained and policed by the parents to ensure fair competition. This class is more about seat time rather than competition racing.
Kids:
No minimum weight
100% box stock predator 212cc (Refer to box stock rules)
Red Restrictor plate.
NO DRILLING OR MODIFICATION OF ANY KIND TO THE PLATE. WILL RESULT IN DQ
If a racer is capable above and beyond their age group it is up to the tracks discretion to ask them to graduate to the next class.
Juniors:
300lb minimum weight
Predator or Ducar 212cc engine.
Factory style air box
Factory head, valves, springs, etc.
Factory bottom end
Aftermarket header allowed
Factory carburetor and BLUE RESTRICTOR PLATE
NO DRILLING OR MODIFICATION OF ANY KIND TO THE PLATE. WILL RESULT IN DQ
If a racer is capable above and beyond their age group it is up to the tracks discretion to ask them to graduate to the next class.
Modified:
236cc Maximum Displacement
No Jackshafts
No Gear Boxes
No 2 strokes
Cast Blocks
$200 protest tear down. Winner of protest will receive the funds. (same for Sport Stock)
Sport Stock:
212cc displacement Predator or Ducar (No Tillotson blocks)
Stock length rod
No methanol fuel
Must be āstock appearingā
6000RPM MAX
(Cheeseburger Follows Same Rules)
No billit
Box Stock:
$200 buyout rule
5750rpm
Factory everything.
-Floor mount tank, and top plate/pulse pump legal but not required. (Per safety updates)
-Predator hemi or non-hemi allowed (no ducar, tillotson, etc.)
-No machining or lightening of crank, rod, or piston
-10.8 pound valve springs
-Factory thickness of head gasket
-Stock heads no swapping of hemi to non-hemi or otherwise
-No shaving of heads
-Factory valve size
-No valve spring shims
-Factory coil
-Factory crank to remain un-tampered with all casting marks in tact
-Factory rod to remain un-tampered with all casting marks in tact
-Factory blocks only
-Factory crank bearings only
-Factory bore and jet size In carburetors no boring or jet modifications allowed
-Stock length rod only no billets or aftermarket allowed
-Governor may be bypassed at racers discretion
-Factory flywheel no billet, pvl, or ghost flywheels
-flywheel must have stock plastic cooling fins, no cutting of fins allowed
-no porting or polishing of the head
-no aftermarket valve covers
-hole MAY be drilled in gas cap to prevent v***r lock
-no modifications to air box. Factory air box for style of motor and factory filters. No drilling of holes or porting allowed
-factory muffler. Must have all baffles and mesh in tact
-factory on/off switch only
-low oil sensor may be unplugged but must stay in the motor
-87 fuel only. No octane boost, methanol, or fuels otherwise that are not pump gas 87 octane
-no swapping of parts from hemi to non hemi, or non hemi to hemi
-factory rocket arms no ratio rockers, roller rockers etc.
-factory push rods, no chromoly or altered lengths allowed. .157 diameter .190 Ball
-factory tappets
-factory pistons only. No swapping non hemi to flat top
-Stock 2.756 mm bore
Stock 2.165 mm stroke
Stock .785/1.000 stroke
Stock cam .224/230 lift206/.210 duration
-factory camshafts only. If it came in a dynocams box it is ILLEGAL
-factory valve caps only
-factory valves only. No aftermarket valves of any kind. Stock 27/25 mm valves, Stock 5.5 mm valve stems
-factory side covers on block only
-no swapping of crank between hemi and non hemi
-no clocking of the camshaft. Factory alignment dots must match
-no timing adjustments. Must run factory key.
The only thing you may change or modify:
holes drilled in gas cap,
governor adjustments/bypass,
and changing of the spark plugs.
Option of fuel tank relocate
All components otherwise are to stay the way they came out of the box.
