TAG ENGINE TECH
These rules apply specifically to the engines used in IKF Competition. These rules may vary from other organizations' rules. Please check, carefully, that your motor complies with these rules before entering IKF Competition.
Motors approved are for a three year period, thru the year 2017.
Any changes or improvements must be submitted prior to introduction and approved by the IKF TaG Committee Chairman before use at any IKF race. These submittals must be made in writing and must be from the importer or manufacturer only. All TAG engines are to be used the way the manufacturer submitted them for approval.
The intent of these rules is to run the motor as delivered from the factory. Any specifications not specifically covered in these rules will be governed by the principle of "May be compared to a known stock part" for final determination of legality.
For reference on TaG motors, see the IKF website: www.ikfkarting.com under Rule Updates.
675 General IKF TAG CLASS engine specifications
675.1 Where discrepancies in tolerance specifications are found between like components on different engines, the more liberal tolerance will apply.
675.2 AIR BOX: Must be pre-2004 CIK homologated (or registered), K&N with rigid internal filter or RLV with two inlet tubes not to exceed 23.0mm and 95.0mm minimum length. Air boxes may not be modified although the rubber flange may be trimmed on the inside of the air box to the flange lip. Aftermarket internal foam air filters are allowed as long as no modification is made to the air box itself. The position of the air box is non-tech. Rotax air box must remain as per RMC rules. On Parilla Leopard and BM Jaguar only intake silencer adapter 10771-C is permitted. Part #10770 is not permitted.
Airbox must be in place at post race technical inspection.
Other engines using bolt on inlet silencer adapters must also conform to Section 603.1.3. See Section 603.1.4 through 603.1.4.7.
675.3 CARBURETORS/MANIFOLDS: OEM as supplied from the engine manufacturer, open jetting. Must use OEM needle jets but washers may be added for the purpose of tuning. How the throttle cable connects to the arm and the bracket that holds the cable are non-tech. The manifold and carburetor may not be modified. The arm, throttle shaft and butterfly are OEM with no modifications. The slide assembly is included in jetting but must retain OEM replacement parts. Throttle shaft screw must remain stock. Fuel may only pass through stock metering orifices. Any means taken to bypass fuel to the engine in any other manner is not allowed. Any
components not specified herein must be stock. Surface finish of venturi and bore must remain as manufactured.
Engine must be equipped with carburetor as specified by the engine manufacturer. See carburetor dimensions as listed on TAG Carburetor Quick Reference Specifications (PDF) on the IKF website: www.ikfkarting.com under Rule Updates.
675.3.1 BUTTERFLY CARBURETORS: Inlet springs are non-tech item. Machine work to the throttle shaft is not allowed. All pumper style carburetors are single-pumpers with plastic fuel cap. Fuel adjustment needles must be stock from the needle top to the “O” ring step. Needles may be modified beyond the “O”
ring step to attach needle extensions. No remote carb adjusters or triggers.
675.3.2 SLIDE CARBURETORS: Must remain stock as supplied by the manufacturer.
675.4 REED CAGE/REEDS: No polishing or grinding of reed cage allowed. Resurfacing of rubber contact surface area to reeds and gasket surface area is allowed. Removal of excess loose rubber at manufacturing parting lines is allowed. No machine work, polishing or metal removal, or addition, to manifold is allowed. Reed attachment screws are non-tech.
675.5 FUEL PUMPS: must be of diaphragm pulse type, manufacturer and location open.
675.6 IGNITION SYSTEM: must be OEM as supplied by the engine manufacturer. Leopard Digital K ignition is approved. Static timing must be at factory settings, key must be in place. No modifications are allowed. Ignition system must be used as supplied in its entirety. Spark plug is open, but must be same reach as stock.
675.7 PISTON/RINGS: OEM as supplied by engine manufacturer.
675.8 BEARINGS: Must be of original type as per engine manufacturer’s specifications; i.e.: 6205. No dual-row, ceramic ball, or other exotic bearing allowed.
675.9. INTERNAL MODIFICATIONS: No internal engine modifications are allowed including the addition or deletion of any parts, i.e., gaskets, nuts, bolts, etc.
675.10 SEALS: Must be of original type and size per manufacturer’s specifications with no modifications. No trimming or spring removal. Must be installed as manufacturer intended, i.e. not reversed.
675.11 GASKETS: Gaskets must be in place, thickness and manufacturer are open.
675.12 EXHAUST SYSTEM: Exhaust system and silencer must be stock OEM as per engine manufacturer. Exhaust system components must be intact and in place for post race technical inspection
675.12.1 Exhaust connector pipe: Exhaust connector pipe must be flex tubing (except PRD which will use OEM solid connector pipe). Connector pipe length is non tech, but overall length of exhaust system must conform to manufacturers’ specifications.
675.12.2 Header and pipe: Must be used as supplied by manufacturer. No plating or ceramic coatings permitted. Exhaust system must start and complete race intact as intended for use by the manufacturer.
Addition of exhaust gas temperature lead is allowed. Exhaust temperature fitting must be welded or brazed in place. Pipe clamp types are not allowed. If temperature probe is not in place in the fitting, the fitting must be plugged.
675.12.3 Solid connector pipe is allowed for Road Race only.
675.12.4 In Road Race only, minimum flex length for Sonik VX is 3.125" (3-1/8"), for Sonik TX minimum flex length is 3.625" (3-5/8").
675.13 CLUTCH: OEM as per the engine manufacturer. Must be single disc or shoe type only. Slip must not be adjustable. Clutch engagement, for engines listed in Tag Engine Specification chart except Mini/Micro Swift, and Mini ROK, must not exceed 6000 rpm, checked with procedure specified in Sec. 620.19.2. Excessive oil or grease may not be present.
675.13.1 CLUTCH TEST PROCEDURE FOR MINI/MICRO SWIFT AND MINI ROK: Follow procedure below and engagement reading cannot exceed 5000 RPM:
• Place kart on stand in a safe location with axle free to turn with no obstructions.
• Start engine.
• Apply throttle a few times to ensure response.
• Holding throttle and brake on at same time, apply full throttle against full braking without tire rotation.
• It may require a few attempts to get a clean pull.
• Read either competitor’s gauge or have a clip-on tech gauge to read RPM at highest reading.
• RPM's exceeding 5000 are non-compliant.
675.14 COOLING SYSTEM: Radiator is open. Radiator must be mounted to left or right side of driver. Coolant may not contain any Glycol based material. Water wetter or other surfactants may be used. Water pump type must be as submitted by engine manufacturer. Exception: Rotax Max must use radiator as supplied with motor.
675.15 PORTS: The intent is that the ports remain as manufactured. Note: Research has shown that all
manufacturers use some hand grinding to remove casting imperfections as part of their manufacturing process.
However, every effort will be made to distinguish between factory grinding and that done to improve performance by the engine builder or owner.
675.16 CONNECTING ROD: Rod must be of original manufacture. No modification or metal removal allowed.
675.17 CYLINDER HEAD: Cylinder head must be stock, as manufactured part. Cylinder head must be stock appearing in combustion area. (ie. If head comes with a step at gasket surface to squish area, the step must remain visible.) Each engine will have a specific minimum squish area to be checked parallel to the wrist pin with approximately 1/16” solder, checked one side at a time. Should an engine check on one side less then the minimum allowed, the other side is to be checked and the average of the two dimensions will determine the actual squish number. To check the squish, insert the solder and rotate the engine one revolution in the direction that the engine runs. Do not use electric starter. Each engine has its own specific cylinder head combustion chamber volume specification. (Refer to the specification chart.) Engine combustion chamber volume will be checked with head installed and as raced. Fluid level to the top of the spark plug hole. No modifications to circumvent engine cc requirements. (See spark plug.)
675.18 BORE AND STROKE: Measurements are taken from engine as raced and will be plus or minus .2 mm (.008).
Refer to chart for all bore and stroke measurements.
675.19 CRANKSHAFT: Must be of original manufacture. No counterweight plugging is allowed. No metal
removing, shot peening or polishing is allowed. Any rod bearing is permitted. Crankshaft stuffing material may be aluminum or plastic as supplied by manufacturer. Crankshaft must be of the same manufacture as the engine brand as approved by IKF. No interchange between engine brands is permitted. Crankshaft stuffers must be used as approved by IKF. See stroke chart.
675.20 CRANKCASES: Must be as manufactured no polishing or metal removal, other than a break at machine junctions for purpose of deburing. Exception: Main bearing pockets may be repaired but may not be relocated in the process.
See exception for TaG Enduro, Sonik powered laydown karts only, at 302.15.1.1.
675.21 ROTAX MAX: Rotax Max engines used in IKF TAG classes or in Local/Regional option classes are to be run under United States Rotax Max Challenge (USRMC) rules.
Oil ratio for these engines only is to be per current USRMC rules 675.22 OTHER:
Motor mounts are non-tech.
No additional painting, plating or ceramic coatings of any component permitted.
Some engines have been approved with anodized components, which are acceptable.
TAG ENGINE PACKAGE SPECIFICATIONS CHART
THICKNESS IGNITION TIMING CLUTCH CARBURETOR
Motori
FR 125 Use United States Rotax Max Challenge (USRMC) Rules Vortex Rok
1Check using 0.2mm shim, instructions on IKF website.
2See PRD TAG Controlled rules on IKF website
32008 PRD Fireball identified by black anodized cylinder head and machined ports.
4Check PDF on IKF website
5Rev limiter at 15,500 rpm
Combustion chamber volume to be checked to top of spark plug hole with head on engine as raced without LAD tool.
Carburetor venturi diameter checked at narrowest point of venturi.