2023 RULES

 

RULES SUBJECT TO CHANGE WITHOUT NOTICE​

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Block & Side Cover Repair/Modification
Welding of epoxy repair permitted to the block and side cover. Repair may not be a functional modification (performance enhancing). 
Decking of the block is permitted. No pop-up of the piston is allowed.

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Fuel
Pump gas / No Nitro / No Propylene Oxide
OEM tank must be removed.
Any pulse type fuel pump permitted and can be pulsed from the crankcase, side cover, or valve cover.

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Carburetor
Stock Huayi or Ruixing type carb only.
Choke assembly must be in place and functional.
Choke lever must be stock. Drilling holes to mount choke lever is prohibited.
Venturi - .608" Must-Go, .615" No-Go.
Throttle Bore - .751" No-Go.
Throttle Shaft - .115" minimum thickness
Butterfly - .037" minimum thickness, butterfly screw minimum length .305"
Jets - Main jet and low-speed idle jet are non-tech
Filter Adapter - Max 1.375" height. Grinding or modifying spacer between filter adapter and carburetor is prohibited.
Emulsion Tube - through hole maximum ID of .066" No-Go. Minimum length is 1.092" and must have 20 holes on top; hole diameter must be .036" No-Go. Bottom holes can be either 2 or 4 holes. Minimum diameter is .154".
Phenolic Insulator - Must be run between carburetor and block. Plate hole and finish of plate are non-tech. Fuel Bleed off slot must be unaltered. Thickness must be maintained at .257" minimum. Plate must be flat and maintain consistent thickness at all points. 

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Piston
Must be of three ring design. 
Minimum weight of 145 grams with oil expander ring and two rail rings installed. 
Piston length is 1.935" max, 1.910" minimum, .580" max top of wristpin hole to top of piston as measured with a dial caliper.
Standard bore is 2.685", maximum overbore allowed is 2.700".
Piston is not allowed to be any higher than the deck of the block at TDC. 
No flat top piston allowed. must be dished-OEM w/no modifications.
Aftermarket pistons and/or sizes up to .010" over are permitted.
Machining of piston is prohibited.

Piston Rings
Mandatory that all three rings to be intact and functional.
Top ring must be chrome faced.
No alterations of rings are permitted. 

Ring Tension Requirements
Top two rings must support themselves. in the cylinder when removed from piston. They cannot fall through the cylinder.
Bottom ting is a non-tech item regarding tension. Bottom expander ring & two rail rings, when mounted on piston and rod in place should support piston in cylinder when inserted upside-down.
Ring Tension Inspection Procedure
Top two rings must support themselves without assistance in cylinder.
Each of the top rings should be placed, indivdually, approx. one inch down in the cylinder.
Square ring with piston turned upside down. 
If ring supports itself, it is legal.

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Crankshaft
Standard OEM item with stock stroke of 2.126" (+/- .007")
No alterations permitted
Journal diameter must be between 1.168' - 1.180"
If needed to prove lack of modification, crankshafts minimum weight would be over 1700 grams.

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Ignition Coil
Must be OEM for all classes
Timing is non-tech

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Flywheel
Flywheel key may be altered and is non-tech; key is not required to be installed.
Flywheels must have a minimum weight of 3.3 pounds.
Modifications or removal of fins is prohibited.

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Cylinder Head
Only JT 4-Bolt heads and TG-1 heads will be allowed.

Sanding and Machining: No sanding or machining of carburetor or exhaust mounting surface.

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Valve Seats
Valve seats can have up to three angles as cut by the manufacturer:
60-degrees bottom relief
45-degrees top relief
30-degrees top angle relief
Porting, grinding or matching to the ports or combustion chamber is prohibited
Top of valve cannot be below floor of combustion chamber (cannot sink the valves)
No angle milling of head. Measurement taken from gasket surface: depth check to combustion chamber floor cannot vary more than .005" in any direction.

Minimum Combustion Chamber Volume
Minimum combustion chamber volume when mounted on engine at TDC is 26.5 cc's. This is to be done after the event and when the engine has cooled down to a reasonable temperature. 

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Head Dimensions
Max head thickness: 2.640" as measured from the valve breather mounting surface to in-between the valve seats and the combustion chamber. 
Head thickness from the valve breather mating surface to in-between the valve guide is 1.150" max.
Port Depth: measured from the top of the valve seat to the port floor; Intake .880" max, Exhaust .830" max
Valve bowl height gauge is the preferred measurement tool.
Intake/Exhaust Seats
Intake seat: .899"
Exhaust seat: .862" max

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Valves
Steel or stainless steel valves with 45 degree angle only and no lightening or polishing. Polishing or sandblasting of valve stem up to port entrance is allowed; however, polishing of whole valve is prohibited. Cannot be visible above the valve guide.

Valve Dimensions
Intake valve OD: .975" Minimum
Exhaust valve OD: .937" Minimum
Intake valve length: 2.525" Maximum
Exhaust valve length: 2.555" Maximum
Minimum valve weight: 21 grams

Rocker Arms
1:1 Ratio rocker arms only
Rocker arms must be steel and are subject to magnetic test.
Rocker arms are allowed to be ground on valve stem location only, or on bottom of rocker arm to allow running lift to be compliant. Grinding on the sides of the rocker arm is prohibited. No minimum thickness checks.

Valve Springs
Maximum Coil Diameter: .071"
Number of Coils: 4
Spring shims are allowed, no thickness check and must maintain .815" height check including shims
Springs must be made of a magnetic material
Install height .815"; check with must go gauge .815" with retainer in place. Gauge must go in both directions with retainers in place as raced.
Lash caps on exhaust valve only. Intake retainer must retain stock appearance - no length or thickness check. Material must be magnetic
Upper seals optional, seals may be used on both intake and exhaust

Spring Coil Check
Using the Spring Coil Check with a .250" ground tool steel as No-Go gauge.

Weight Check
Using the Weight Check to check tension. 
Maximum Tension: 10.8lbs @ height of .850" and 18lbs @ height of .650"

Pushrod
Length: 5.275" + .010" Maximum
Must be of 3-piece design
Minimum weight: 9 grams

Lifters
Length: 1.350" - 1.390"
Oustide Diameter: .935" maximum
Minimum Weight: 18 grams

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Camshaft
Stock appearing camshaft cores only with the ez-spin assembly unaltered and in stock condition is mandatory.
Cam lobe base circle diameter min/max is .860" - .875"
Duration taken from pushrod. Intake duration of 221 degrees at.050" lift and 88 degrees at .200" lift. Exhaust duration of 224 degrees at .050" lift and 99 degrees at .200" lift. Camshaft tolerances:+2 degrees with no minimum duration check
Intake lift at pushrod is .215"-.225".
Exhaust lift at pushrod is .222"-.232".
Intake lift at retainer is .238" max
Exhaust lift at retainer is .242" max
Lift will be checked as raced.

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Gaskets & Sealers
Gaskets must be OEM configuration and are non-tech and seal may be applied unless otherwise specified. No sealers allowed on intake or carburetor side!
Crankcase gaskets: Maximum two gaskets and/or sealer allowed
Non-performance enhancing marking, "engraving", sanding or other minor modifications to gasket mating surfaces to improve/enhance sealing capabilities is allowed.

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Bearings
Crankshaft bearings shall be of metallic (magnetic steel) construction and be of conventional design and stock appearing and the same dimensions as the OEM bearings. This includes inner and outer races as well as the balls and rollers. No other materials allowed.

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Coatings & Polishing
Coating, tumbling, and/or polishing of internal parts, including carburetor and head, is prohibited.

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Crankshaft Breathers
Crankcase breathers are to be routed internally through the valve cover as originally intended in OEM configuration. No additional breathers allowed.

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Rod
Billet rods are accepted
Honing is allowed but must maintain factory defined edge.
Oil hole size is non-tech

Rod Dimensions
Rod length:2.350"-2.375"
Rod Minimum Weight: 133 grams with cap and bolts

Wrist Pin Dimensions
Wrist pin inside diameter: .555" maximum
Wrist pin outside diameter: .707" +/- .005"
Wrist pin length: 2.100"-2.200"

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Restrictor Plates
Modifications to the restrictor plate is prohibited. The anodizing shall not be removed around the holes in the plate. The plate must be flat. Holes must be as produced, with no rounding of the edges.
Avalible restrictor plates, checked with the blade-type No-Go gauge:
Blue: .550"
Purple: .500"
Green: .425"
Red: .375"

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For Restrictor Plate Classes Only 
RLV Mini 91 Silencer Requirements
Part #4117 
Overall Length 5.470" minimum +/- .005" - 5.600" Maximum +/-.005"
Threaded nipple .685" maximum ID (ID as MFG. No grinding, reaming, or polishing allowed.)
Rear Baffle Holes .1285" maximum
Inner Baffle Holes .0965" maximum
Silencer must be utilized as produced, with no modifications or alterations permitted. 
Strap or brace required to silencer for support, and to insure silencer does not turn or unscrew

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PROTEST PROCEDURE
FEE - $100

-$50 TO TECH MAN AUTOMATICALLY-

-IF FOUND ILLEGAL THE PROTESTER WILL RECEIVE $50-

-IF FOUND LEGAL $50 TO PARTY THAT WAS PROTESTED-

ANY KART THAT IS ON THE LEAD LAP IS ELIGIBLE TO PROTEST THE WINNERS MOTOR. YOU MUST RACE TWO WEEKS PRIOR TO BE ABLE TO CLAIM. YOU MUST PULL IN TECH AREA ACROSS SCALES, GIVE YOUR MONEY TO THE SCALE PERSON.  THIS MUST BE DONE BEFORE THE NEXT FEATURE RACE IS COMPLETED. (DO NOT WAIT UNTIL THE RACES ARE OVER) IF YOU ARE BLACK FLAGGED DURING THE RACE, YOU ARE NOT ELIGIBLE TO PROTEST. IF THE PERSON BEING PROTESTED DECIDES TO NOT ACCEPT THE PROTEST, THEN THEY LOSE THEIR POINTS AND PAY FOR THE NIGHT. IF YOU REFUSE PROTEST TWICE, YOU ARE DONE IN THE CLASS. THESE ARE THE RULES FOR THE CLONE CLASSES, IF YOU DON'T LIKE THE PROTEST RULE DON'T RACE IN THE CLASS.

  
NO OTHER ALTERATIONS TO OR FROM STOCK COMPONENTS ARE ALLOWED.
IF YOU ARE CAUGHT CHEATING IN THE CLASS YOU ARE DONE IN THE CLASS.
EACH CLASS WINNER WILL PULL A CHIP THAT WILL TELL WHAT ITEM WILL BE TECHED.