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Moe's Karting World Inc. Engine and Weight Rules


For all plate and stock classes  WKA guidelines apply. Silicone  non tech item. Carb- 2 ports have to be there but are a non tech item. You can use a Weisco piston (1977& 1978) for all Stock and Hillbilly Classes. All plate and stock classes  mandatory muffler. All plate classes mandatory full bumper and chest protector.


Class - (Alternate Classes) Age Limit Weight

1st Year

Junior Crate 1(silver plate box stock)

(5-8 year olds)

(5-8 year olds)

 

265 lbs

Purple Plate (5-8 year olds) 250 lbs
Junior Crate 2(blue plate box stock) (9-11 year olds) 290 lbs
Blue Plate (9-11 year olds) 265 lbs
Junior Crate 3 (12-15 year olds) 320 lbs
Gold Plate (12-15 year olds) 300 lbs
JR Unrestricted - Flathead Only (15 Max age w/Discretion) 300 lbs
JR Unrestricted - (Hillbilly, Stock Animal, Super Box) (15 Max age w/Discretion) 325 lbs
Stock Lite (15 - up) 325 lbs
Stock Heavy (15 - up) 375 lbs
Adult Crate  (15-up) 375 lbs
Hillbilly Extreme(WKA animal/super box stock)   350 lbs
ProStock (15-up) 340 lbs
Limited Mod (308 animal with tilly) (15-up) 360 lbs
Flathead Extreme   360 lbs
Open/UAS - UAS rules apply (15-up) 360 lbs
Refer to: www.bergfeltracing.com/unlimitedallstars.html
30 and over Class(Hillbilly motor) (30-up) 350 lbs
Money Races - Flathead only - WKA Stock   350 lbs
 




1st Year is a blue box stock with a governor motor straight out of the box.  Governor is 3600 RPMs.  Governor is with out the purple plate.  Drum clutch only.  AKRA guidelines apply for all crate classes.  UNLESS OTHERWISE STATED ENGINES WILL BE TECHED AS RACED.


Engines

1st Year

Junior Crate 1(silver plate box stock)

AKRA Guidelines Apply

AKRA Guidelines Apply

Purple Plate WKA Guidelines Apply
Junior Crate 2(blue plate box stock) AKRA Guidelines Apply
Blue Plate WKA Guidelines Apply
Junior Crate 3 AKRA Guidelines Apply
Gold Plate WKA Guidelines Apply
JR Urestricted WKA Guidelines Apply
Stock Lite WKA Guidelines Apply
Animal Stock WKA Guidelines Apply
Stock Heavy WKA Guidelines Apply
Adult Crate Class 6 1/2 Honda Clone
Money Races WKA Stock

 

No Clone motors with flatheads unless restrictor plate sizes match. Weight determined by track scales no tolerance. For special events and money races the restrictor plate and age group may apply. No fuel additives (this included top lube) 100% methanol only - NO NITRO AT ALL


There will be profile checks for these above classes

 

Box Stock Clone


  1. AKRA rules apply. Pipe and air filter kit can be used.
  2. APS - 6931 Air filter, JC Specialty 106931 Air filter or ARC 6931 Air Filter.-max length 1.375"
  3. Engine clutch only.  Either drum or disc clutch.
  4. Fuel tank is Non Tech. (highly recommended that for safety reasons remote/floor mounted tank be used)
  5. Huayi carburetors allowed.  All stock carb gaskets must be present.  Choke assembly not required.  Choke bore, .810" NO-GO, and Throttle bore .751" NO-GO.  Main fuel jet and Low Speed Idle jet may be drilled to any size NO-GO.  Emulsion tube must remain stock 0.064" NO-GO.
  6. Any pulsed type fuel pump is allowed.  Fuel pump must be pulsed from valve cover.  *Any other way to pulse must be approved by Track Tech.
  7. Block Requirements:  Stock Block, as cast and produced with no alterations or modifications other than those specifically permitted.  Max bore is 2.685". Stroke is 2.123" puls or minus 0.005".  Stub for governor may be removed and hole plugged.  Additional side cover gaskets as required for crankshaft thrust are permitted.  Welding to the block shall be for rod damage repair only and may not constitute a functional modification.
  8. Combustion chamber volume: 26.5 cc's, with piston at TDC, using prescribed procedure.
  9. Cylinder head must be OEM casting only.  Porting and/or grinding are not permitted.  Valve seats are two angles 45 degrees valve face and 30 degrees top relief.  Head gasket must be stock configuration.  Spark plug is a non tech item.
  10. Valve train will remain stock.  No polishing, grinding, or alterations.  Stock 1:1 ratio OEM rocker arms only.  Stock valve springs only.  max wire diameter is .0705". Max spring pressure is 10.8 lbs. at an installed height of 0.850".
  11. Connecting rod: Stock rod only; no modifications.
  12. Crankshaft: Standard OEM item with stock stroke length of 54mm or 2.126"(+/- .005"). Machining, olishing, addition of material or other alterations are prohibited.  Stock factory timing gear mandatory and must be installed in original location.  Crankshaft journal diameter is 1.180" -1.175" min.
  13. Pistons:  OEM Std. bore (68mm or 2.677") only.  Three ring design and all rings to be intact and functional.
  14. Stock as cast camshaft only.  Cam lobe base circle diameter .865" -.005"/+.010".  Duration check for Intake and Exhaust lobes (taken off pushrod).  Intake duration of 218.5 degrees at .050 lift/85.5 degrees at .200 lift.  Exhaust duration of 221.5 degrees at .050 lift/96.5 degrees at .200 lift.  (All checks will allow +2 degrees for wear and gauge variances.)  Note-The camshaft has a compression release and it needs to be taken into account when zeroing the indicator on the exhaust lobe.  The compression release does not need to be intact and functional.  Dyno CL 1 cam does fall within these specs.  Max Intake Lift on cam .225" taken at the pushrod.  Max Intake Lift at the valve .238" taken on valve spring retainer with zero lash./Max Exhaust Lift on cam .232" taken at the pushrod.  Max Exhaust Lift at the valve .242" taken on valve spring retainer with zero lash. 
  15. Flywheel and Ignition Coil:  OEM stock/unaltered flywheels and plastic fins only.  (no machining allowed).  Timing can be advanced up to 8 degrees.  Plastic fins must remain stock, no shaving or cutting of fins.  Stock coil only.
  16. Header can be of single stage or multi stage configuration.  Length of header a maximum of 20".  RLV muffler must be installed and baffles must be intact.  No loop headers.
  17. The pull starter is non tech and optional.  It may be removed to allow the use of an auxilliary (hand held) starter or different brands of pull starters can be used on any of the approved engines.
  18. Engine oil recovery system mandatory.
  19. Oil sensor may be removed.
  20. Governor and governor components are non-tech.
  21. GAS ONLY! 87 octane max.

Super Box Stock


  1. AKRA rules apply.
  2. Pipe - ARC # DJ1137, APS # RLY5438C or JC Specialty # 131137.--20" max
  3. Super Box Stock Kit - ARC # DJ1031
  4. You may drill high and low on carburetor and adjust timing.
  5. Tank is optional, any clutch.
  6. GAS ONLY!

Hillbilly Extreme


  1. Engine must start as a stock flathead 5hp Briggs and Stratton. Blocks may be patched or welded to fix holes and cracks.
  2. Blocks may be decked. Any popup is allowed.
  3. Top of block may be modified. (example - remove eyebrows)
  4. Block can be ported and polished. No adding of any material to the ports.
  5. Must use stock style carb. and tank combo (no fun carb). Max bore is .750 on Carb.  Carb may be machined to improve flow. No billet aftermarket carbs. No newer ventri style carbs. No welding except to plug OEM choke holes. Products like JB Weld can be used to fix choke holes on outside of carb. It cannot be used to build up a carb to be bored bigger or used to enhance performance. CRACKS and PLUGGING holes ONLY!
  6. Air filter adapters NON-TECH.
  7. Any stock type Briggs ignition coils (stock appearing). Air vane can be removed.
  8. Connecting rod has to be stock length. Can run Billet like 3.870" or 3.875" ARCrods.
  9. Piston has to be stock Briggs Raptor or Weisco (1977 & 1978) allowed.
  10. Any cam with a max lift of .233" is allowed. This is running lift. Checked as ran. Just pull head and put dial indicator on valve and measure.
  11. Briggs 5hp OEM stock valves only . Valves may have multiple angles, stock seats but may be modified, any valve springs are allowed, dual springs are OK. Aftermarket breather is allowed. Stock or single plate breather only. No ARC type breathers.
  12. Billet lifters are allowed (extended lifters are OK)
  13. Stock Briggs cranks only (2.4375" +/- .010) stock stroke.
  14. Max overbore will be .035 + .010 does not mean .040" pistons are ok!
  15. Head is stock appearing. May be relieved to make clearance for valves. Must start with Briggs stock head. No repositioning of spark plug hole.
  16. Lifter bores may be welded for strength, and cut for cam clearance.
  17. Flywheel must be Stock (steel only) 5hp flywheel. NO machining or rebalancing at all. OEM Unaltered ONLY!
  18. Any header is allowed.
  19. Fuel is Methanol Only. No pressurized fuel systems!
  20. Any clutch is allowed.
  21. Combined kart/driver min. weight 350lbs.
  22. If it isn't listed here you cannot modify it or run it!

ProStock Engine Rules Flathead


  1. Engine must start as a stock flathead 5hp Briggs and Stratton. Blocks may be patched or welded to fix holes.
  2. Block may be decked. Any popup is allowed.
  3. Top of block may be modified. (example - remove eyebrows)
  4. Block can be ported and polished. No adding of any material to the ports.
  5. Must use stock style carb. and tank combo (no fun carb). Carb may be machined to improve flow. No billet aftermarket carbs. No newer ventri style carbs. No welding except to plug OEM choke holes. Products like JB Weld can be used to fix choke holes on outside of carb. MAX bore .715". It cannot be used to build up a carb to be bored bigger or used to enhance performance. CRACKS and PLUGGING holes ONLY!
  6. Air filter adapters NON TECH.
  7. Any stock type Briggs ignition coils. (stock appearing) Air vane can be removed
  8. Connecting rod and piston is non tech item
  9. Any cam with a max lift of .316" is allowed. No roller type cams. This is total lift with death valves or shines under the valves for zero lash and dial indicator zeroed at TDC.
  10. Oversized valves and seats allowed, any valve springs are allowed, dual springs are OK. Aftermarket breather allowed. Stock or single plate breather only. No ARC breathers.
  11. Billet lifters allowed. No roller type lifters.
  12. Stock Briggs crank only (2.4375" +/- .010"). May be heat treated and relieved for max cam lobes to clear.
  13. Max overbore will be .060 + .010".
  14. Head is stock appearing. May be relieved to make clearance for valves. Must be Briggs stock head. No repositioning of spark plug hole.
  15. Lifter bores may b welded for strength and cut for cam lift clearance
  16. Flywheel must be stock 5hp flywheel. No machining at all. May have rare earth magnets installed or billet aluminum ARC part# 6608, Clements flywheel part # BAFWL and # FWSLTD, JR Racecar flywheel part # 555-3284, or United machine and Fabrication part # 1001.
  17. Any header is allowed.
  18. Fuel is methanol (only) No pressurized fuel systems!
  19. Any clutch is allowed.
  20. Combined kart/driver weight 340lbs.
  21. If it isn't listed here you cannot modify it or run it!

ProStock Animal �


  1. 308 cam
  2. dual valve spring kit � these are the only changes that can be made
  3. Stock rod #s 6249, 6250, 6251 can be run with a 308 cam
  4. Combined kart/driver weight 340lbs
  5. If it isn�t listed here you cannot modify it or run it!

Limited Modified Engine Rules


  1. Engine must start as a stock flathead Briggs and Stratton
  2. Block may be decked. Any popup is allowed.
  3. Top of block may be modified. (example - remove eyebrows)
  4. Blocks can be ported and polished. No adding of any material to the ports.
  5. Carb is a NON TECH ITEM. Intake is NON TECH excepts has to be bolted on. Cannot be welded on.
  6. Any stock Briggs ignition coils. (stock appearing) Air vane can be removed
  7. Connecting rod and piston is a non tech item.
  8. Any cam is allowed. No roller cam.
  9. Stock valves only. Valves may have multiple angles. Stock seats but may be modified. Any valve spring allowed, dual springs are OK. Aftermarket breather is allowed. Stock or single plate breather only. No ARC type breathers.
  10. Billet lifters are allowed (extended lifters OK). No roller type lifters.
  11. Stock stroke cranks only (2.4375" +/- .010"). May be heat treated and relieved for cam lobes to clear.
  12. Max Overbore will be .060 + .010.
  13. Head is stock appearing. May be relieved to make clearance for valves. Must start with Briggs stock head. No repositioning of the spark plug hole.
  14. Lifter bores may be welded for strength, and cut for lifter clearance.
  15. Flywheel - 3hp or 5hp Billet mandatory - either unaltered.
  16. Fuel is Methanol ONLY. No pressurized fuel sytems!
  17. Any clutch is allowed.
  18. Combined kart/driver min. weight 360lbs.
  19. If it isn't listed here you cannot modify it or run it.

Flathead Extreme � (15 and up)


  1. Must be a flathead, Raptor, Blockzilla, Briggs & Stratton ONLY
  2. Any carb, any stroke, and bore
  3. Combined kart/driver min weight 360lbs.

Open Engine Rules - UAS rules apply


Refer to: www.bergfeltracing.com/unlimitedallstars.html

  1. weight/kart driver min weight 360lbs.