2009 IKF Regional Option Class
West Coast Stock CR80 Sprint
Same rules and specifications as IKF Formula 80 Senior. Refer to 2009 IKF rule book - section 306 & 307.
Exceptions: No front brakes.
Honda CR80 / CR85 only.
Stock OEM cylinder, cylinder head, and ignition.
Complete engine rules are listed below.
|16 years of age minimum|
|No compound or manufacturer restrictions.|
Chassis: Sprint sit-up shifter - no front brakes.
Engine: CR80 / CR85 (Exclude 2005 & newer CR85) with 8.5 min CCV. Stock OEM ignition box. Aftermarket 3rd gear allowed. Legacy cases allowed through 2009.
|Two 20-minute heats.|
Conditions And Definitions Specific To This Class
Guidelines offered in these pages are subject to the term "Spirit and Intent" and apply to the technical aspects of this "Stock" shifter kart class. It is expected that all participants will adhere to the spirit and intent of these rules. These are guidelines for fair and equitable competition. They are not the basis to "read between the lines" in order to circumvent the intent.
Spirit And Intent: "If these paragraphs do not say you can, you can't!"
Stock Defined: All displacements will bear a tolerance that will be defined by specifications deemed as "Factory Stock," in specifications from said manufacturer. All post event technical inspection will rely on published factory specifications and may be compared to known stock parts.
Neither the OEM engine nor any of its auxiliary components may be modified in any way, unless an exception and / or exclusion is specifically noted within the rules. This includes the addition, deletion and / or omission of and / or adjustment to parts and / or materials. Note: Adjustments to components that are specifically designed for that purpose shall not be construed to be a modification (i.e. Carburetor jets, needles, slides, adjustment screws, spark plugs, exhaust flange spacers, etc.).
OEM Defined: For purposes of defining allowable engine components, OEM will mean parts produced by a particular manufacturer for a particular model. Where OEM parts are called out for example, you may not use Yamaha parts in a Honda engine, or Honda RS parts in a Honda CR engine. Except where otherwise stated, the year of manufacture is open, provided the parts are commercially available in the U.S. market.
Engine: Accepted engine in this class is restricted to a pre-2005 Honda CR80 / CR85. Maximum displacement is 83.0cc / 85.0cc.
Top End: Cylinder and cylinder head must be stock OEM. The water outlet(s) in the head must remain in the stock location, in relation to the exhaust port.
CCV: Minimum 8.5 CCV, measured with a L.A.D. tool (part #CCMP). Head gasket must be stock OEM. Base gaskets of varying thickness may be utilized to obtain the target 8.5 CCV.
Cylinder may be honed, but may not be repaired, if damaged.
Piston, ring, wrist pin, and upper rod bearing must be stock OEM.
Exception: For the purpose of cooling / lubricating the exhaust bridge, up to a maximum of two holes may be drilled (0.0625 inch maximum diameter), in the exhaust side of the piston.
Bottom End: Crank, rod and flywheel assembly, including bearings and seals, must be stock OEM. Exception: Sanding / polishing to allow for slip fitting of bearings to crank is permitted.
Carburetor: Box stock Mikuni TM 28mm carburetor. Bore may not exceed 28.6 mm in diameter, through the 0.400 inch throat, measured inboard (engine side) of the slide.
Fuel Pump: Pump around fuel recirculation system is allowed. Single, pulse type pump feed system. One (1) pump feed only. Any additional pump must be for evacuation (i.e. pump around system). No electric or belt driven pumps. Catch containers and / or alternative plumbing are mandatory, to deal with potential carburetor overflow.
Manifold And Reeds: Intake manifold and reed assembly must be stock OEM. Note: Bending of the reed stops is allowed.
Intake Noise Suppression: Air boxes are required, only when local authority mandates. IKF rule 603 applies.
CDI: The CDI, spark coil, wiring and connectors must be stock OEM.
Exception: The wires connecting the coil and stator to the CDI may be lengthened or replaced, to facilitate mounting of the CDI unit. The addition and use of a coil ground cable is recommended. Kill switch, if used, must function only to kill the engine.
Note: The events technical director may require a competitor to swap CDI boxes, prior to the start of a race event. Failure to comply will result in disqualification for the day.
The stator, pickup, and flywheel must be stock OEM.
Spark Plug: The spark plug manufacturer is open, but the plug must be commercially available and shall measure 18.5mm long by pitch M14 x 125. Exception: The spark plug washer may be removed to facilitate the use of a cylinder head temperature sensor and the gap of the electrode may be adjusted.
Exhaust System: Same as IKF 653.7. Note: The intent is to have a spec pipe and silencer, for the 2009 race season (spec pipe and silencer, for 2009 race season, to be determined).
Transmission / Clutch: Stock OEM 6-speed transmission. All transmission and clutch components must be stock OEM.
Exception: Finish on gears is a non-tech item. An aftermarket 3rd gear may be used, as long as the tooth count is the same and it is not lighter in weight than the OEM part.
Shifter must be a manual mechanical apparatus.
Note: While air / electric / pneumatic shifters are not allowed, this restriction may be waived to accommodate special driver needs and requires prior written approval by NCK.
External Modifications: Cases must be stock OEM. Exception(s): Kick-starter assembly may be removed and the hole plugged. The case may be clearanced to accept a larger front drive gear. A hole may be drilled and threaded, to accommodate a pulse line. Accessory mounting brackets and locations are open. Timing cover is non-tech.
Other: OEM water pump must be retained. No axle or external water pump allowed. Cooling system may use only water and / or water based coolants. The size and routing of the cooling hose(s) is open. Catch containers and / or alternative plumbing is mandatory, to deal with potential carburetor and radiator overflow. Chain guards are required (steel is recommended). Use of a sprag axle hub assembly is permitted.
Legacy Motors are allowed in NCK competition, during the 2008 and 2009 seasons only.
Competitor must declare that they are using a "Legacy Motor" DURING or PRIOR to pre-race tech inspection. A weight penalty may be assessed, to offset any small gain in performance derived through the use of a modified crankcase. The race director / events technical director may increase or decrease the weight assessment (0 to 20 pound range), upon review of on track performance.
Legacy motors are defined as engines with material added or removed from inside the crankcase, aftermarket bearings, and aftermarket clutch components. Other than machining / modifications within the crankcase areas, a legacy motor must comply with the rules as written.