All Clone classes in WKA West regional series will follow these specifications:
JUNIOR 1 CLONE
Age 7-12. Weight 255 Lbs. Tires 4.5 YLC. Will run .500 purple intake restrictor.
JUNIOR 2 CLONE
Age 12-15. Weight 320 Lbs. Tires 4.5 front / 6.0 rear YLC. Will run .550 blue intake restrictor.
Age 15 and up. Weight 360 Lbs. Tires 4.5 front / 6.0 rear YLC. No restrictor
SENIOR SUMO CLONE
Age 15 and up. Weight 400 Lbs. Tires 4.5 front / 6.0 rear YLC. No restrictor
711 CLONE CLASS ENGINES
Section 711 describe the specifications for clone class engines. These are 6.5 horsepower "Clone" engines only. All parts must be factory production parts unless otherwise specified in this manual. No machining or alteration of parts permitted unless specifically noted. All parts are subject to be compared to known stock parts + or - .005". No reading between the lines. If it is not in the rules, it must remain stock. Additional rules may be added at any time as WKA West moves forward with this program
UNLESS OTHERWISE STATED ENGINE WILL BE TECHED AS RACED.
All classes must run a shoe type clutch. Drum may be stamped or billet steel. No cooling fins may be either machined into drum or added on. Disc clutches are not allowed.
711.2 FUEL TANK
Must be floor mounted
Carburetor requirements: Huayi OR RUI*ING carb only. Carb to intake sealer is gasket only no other sealer allowed. Choke must be as supplied from factory, but may be fixed to stay in open position. Venturi .615” NO-GO. Rear carb bore .751” NO-GO. Main fuel jet .042” NO-GO. Low speed jet size is non tech. Low speed jet may not be drilled through to outside air. Stock emulsion tube must be used and unaltered, .066’ max ID (no pass through). Side holes in E-Tube 4 holes max in bottom section and 20 holes max in top section. Minimum E-Tube length 1.092”. Throttle shaft - .115” minimum. Butterfly - .037” minimum.
711.4 FUEL PUMP
Any pulse type pump is allowed. Fuel pump must be pulsed from the valve cover.
711.5 AIR FILTER
Aftermarket air filter OK, aftermarket air filter adapter allowed (max length of 1.375). Loss of air filter during a race does not constitute a reason for disqualification
Block must remain stock, Maximum bore is 2.685. No piston pops up allowed. Mating surfaces of block is non tech. Surfacing to correct gasket failure and meet cc check is allowed. Solid dowel pins ok for side cover. No welding on block
711.7 CYLINDER HEAD
No porting, grinding or modification. Valve seats may have three angles: single 45 degree valve face and single 30 degree top,and 60 degree botton. Intake seat 0.897" maximum. Exhaust seat 0.862 maximum. Surfacing to correct gasket failure and meet cc check is allowed. No welding on head. Head gasket must be stock configuration, 0.08 min to .040 max. Sealer may be used
711.7.1 COMBUSTION CHAMBER VOLUME
Minimum volume 26.5cc as measured through spark plug hole using the LAD tool with head on the engine. See Section 504 for instructions how to use the LAD tool to check cylinder head volume.
711.8 VALVE TRAIN
Valve train will remain stock. No polishing. No grinding. No alterations. Stock OEM rocker arms only.
Stock valve springs only. Maximum wire diameter is .071". Maximum spring pressures are 10.8 lbs @ height of .850 and 18 lbs @ height of .650". Spring retainer measurements - exhaust 0.250" MIN, intake 0.230" MIN. Intake valve diameter - 0.985" + or - 0.005" with 45 degree angle. Exhaust valve diameter - 0.948" + or - 0.005". Lash cap on exhaust valve only. Seals allowed on intake an exhaust valves. Minumum valve spring installed height is 0.815". Valve spring shims allowed.
Stock rod only. Rod may be honed. no other modifications allowed.
711.10 PISTON AND RINGS
Stock piston and rings only. Ring gap may be filed to fit
Stock crankshaft only;no modifications. Crankshaft journal is 1.180" maximum and 1.168" minimum.
Stroke is 2.123" plus 0.010" or minus 0.010".
Camshaft must meet these specifications. Maximum running lift on exhaust is 0.242" taken on valve spring retainer at zero lash. Maximum running lift on intake is 0.238" taken on valve spring retainer with zero lash. Intake lift at pushrod - maximum - 0.225", minimum 0.215. Exhaust lift at pushrod – maximum 0.232", minimum 0.222. Duration check for intake and exhaust lobes. Intake duration of 218.5 degrees at 0.050" lift / 85.5 degrees at 0.200 lift. Exhaust duration of 221.5 degrees at 0.050" lift / 96.5 degrees at 0.200" lift (all checks will allow +2 degrees for wear and gauge and wheel variances.
711.13 FLYWHEEL AND IGNITION
Ignition coil must be stock, but ignition timing is non tech. Coil may be shimmed to align with magnet. Flywheel must be billet steel, @ 5 lbs 3 ozs. Plastic fins must remain stock. Flywheel key is non tech.
711.14 HEADER PIPE
Maximum length is 15" and minimum is 10". Header must be single stage maximum 0.750" outside diameter, 0.635" ID inside measurement. no aftermarket coatings of any type allowed. 1 header gasket only. Sealer is permitted.
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 and unscrew.
Pull starter must be present and remain stock. Pull starter may be rotated for better cranking angle.
711.17 ENGINE OIL RECOVERY SYSTEM, FILL AND DRAIN PLUG
Hose ran from valve cover breather hole, must be run to a catch can. Oil fill and drain plugs must be safety wired along with bottom two side cover bolts.
711.18 OIL SENSOR
Oil sensor may be removed.
Governer and governer components are non tech.
711.20 SIDE COVER GASKETS
2 gaskets maximum.
711.21 AFTER MARKET COATINGS
No aftermarket coatings of any kind are allowed except on blower housing shroud.
711.21 SHEET METAL
All sheet metal must be used as supplied with engine.
Fuel for all clone classes will be pump gas.
Claimed motor will consist of complete motor less flywheel as supplied from BSP. Amount of claim is $300 cash only and could be subject to change with the market value, CLAIM CONSENT forms must be filled out and signed with entry form in order to recieve series points. CLAIM form will be filled out, signed and put in a sealed envolope along with $300 cash by RACER, then given to Tech Official prior to start of Main Event
After checkered flag, envelopes will be opened and handed out acordingly. Claimer must be a DRIVER in same class, Only one claim per season can be made by a competitor, Claimed engine will be subject to TECH done on that day, If CLAIMED motor is found to be ILLEGAL or DAMAGED in race, the CLAIMER will be given option to proceed with or withdraw thier claim