NATIO NAL HOMOLOGATION FORM Homologation N 110H ENGINE Manufacturer Make Model Validity of the homologation Number of pages BRP-POWERTRAIN GMBH & CO KG ROTAX 125 MICRO MAX 6 years 25 Plus Appendix This Homologation Form reproduces descriptions, illustrations and dimensions of the engine at the time that Karting Australia conducted the homologation. PHOTO OF DRIVE SIDE OF ENGINE PHOTO OF OPPOSITE SIDE OF ENGINE Signature and stamp of Karting Australia Les Allen National Technical Commissioner 27 May 2015 Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 1
PHOTO OF DRIVE SIDE OF THE COMPLETE ENGINE Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 2
PHOTO OF OPPOSITE DRIVE SIDE OF THE COMPLETE ENGINE Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 3
PHOTO OF THE REAR OF THE COMPLETE ENGINE Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 4
PHOTO OF THE FRONT OF THE COMPLETE ENGINE Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 5
PHOTO OF THE COMPLETE ENGINE TAKEN FROM ABOVE Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 6
PHOTO OF THE COMPLETE ENGINE TAKEN FROM BELOW Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 7
TECHNICAL INFORMATION A CHARACTERISTICS The number of decimal places must be 2 or comply with the relevant tolerance. Tolerances & remarks Cylinder Volume of cylinder 125cm³ <125cm³ Original bore 54mm -- Theoritical maximum bore 54.08mm -- Original Stroke 54.5mm -- Number of transfer ducts, cylinder/sump 5 / 3 -- Number of exhaust ports / ducts 1 -- Volume of the combustion chamber 8.9cm³ minimum Volume of the combustion chamber in the cylinder head 11.6cm³ minimum Crankshaft Number of bearings 2 -- Diameter of bearings 30MM 0.1mm Minimum weight of crankshaft 2200 g minimum All parts represented on page 17 photo Balance shaft Minimum weight of balance shaft 255g minimum Percentage of balancing TBA % minimum Connecting rod Connecting rod centreline 100mm 0.2mm Diameter of big end 26mm 0.05mm Diameter of small end 19mm 0.05mm Min. weight of the connecting rod 100g minimum Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 8
Piston Number of piston rings 1 Min. weight of the bare piston 125g minimum Gudgeon pin Diameter 15mm 0.05mm Length 45.6mm 0.15mm Minimum weight 32.1g Minimum Clutch Minimum weight 1000g minimum Of all the parts represented on the page 21 technical drawing B OPENING ANGLES Of the inlet (main transfer ports) 119.5 2 Of the inlet (secondary transfer ports, for 5 transfer ducts engine) 120 2 Of the exhaust 178 2 Of the boosters 118 2 * Angular reading by inserting a 0.2 x 5mm gauge. C MATERIAL Cylinder head Cylinder Cylinder wall Sump Crankshaft Connecting rod Piston ALUMINIUM ALUMINIUM GILNISIL COATED ALUMINIUM STEEL STEEL-ALLOY ALUMINIUM Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 9
D PHOTOS, DRAWINGS & GRAPHS D.1 CYLINDER UNIT EXPLODED DRAWING OF THE CYLINDER, CYLINDER HEAD AND EXHAUST MANIFOLD UNIT * For 125 Micro Max / 125 Mini Max only! To achieve the defined minimum squish gap, one Restriction Plate with same shape as cylinder base gasket in combination with at least two cylinder base gaskets (one below the spacer and one above the spacer) must be used.the squish gap must be measured with a certified slide gauge and by using a 3 mm tin wire (Rotax Part No. 580 132). Squish Gap for 125 Micro Max / 125 Mini Max only! 125 Micro MAX/evo minimum = 2,40 mm 125 Mini MAX/evo minimum = 2,40 mm Without screws or gaskets. The aim of the exploded drawings is to identify the principles, the functioning and the whole mechanical unit Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 10
Section D.1 DRAWING OF THE CYLINDER DEVELOPMENT Indicate on the drawing : B1/B2 = minimum thickness of the inlet (transferts) ribs. A1/A2/A = maximum inlet width measured at the chord. E1/E2 = minimum thickness of the exhaust rib (if existing). C1/C2/C = maximum exhaust width measured at the chord. DRAWING OF THE CYLINDER BASE without dimensions PHOTO OF THE CYLINDER BASE Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 11
Section D.1 DRAWING OF THE CYLINDER HEAD AND OF THE COMBUSTION CHAMBER without dimensions PHOTO OF THE CYLINDER HEAD PHOTO OF THE COMBUSTION CHAMBER IN THE CYLINDER HEAD Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 12
Section D.1 VERTICAL CROSS SECTION VIEW OF CYLINDER WITH LINER, without dimensions PHOTO OF THE CYLINDER FROM ABOVE PHOTO OF THE CYLINDER FROM RH SIDE Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 13
... Section D.1 TRANSFER DUCTS VOLUME Transfer position on 5-transfer cylinder Transfer position on 3-transfer cylinder TRANSFER No. VOLUME in cm 3 Transfer No. 1 LH --.-- +/- 5 % LH 1 RH 1 LH 2 RH 2 5 LH 1 RH 1 3 Transfer No. 2 LH --.-- +/- 5 % Transfer No. 3 or 5 --.-- +/- 8 % Transfer No. 2 RH --.-- +/- 5 % Transfer No. 1 RH --.-- +/- 5 % EXHAUST DUCT LENGTH ANGLE in Minimum in mm -- +/-1 -- mm The L min. dimension will be the result of the value taken on the reference engine minus 5 mm. Technical Drawing No.13 N/A TO 125 MICRO MAX A: Centring guide centred in relation to the exhaust duct by the exhaust manifold fixation screws, with a total thickness of 20 +/- 0.05 mm and being drilled in its centre by a hole with a 5 mm diameter, H7 bore. B: Control gauge composed of a shaft with a 5g6 diameter having a 2.5 mm radius at its end and a length = L min + 20+10. Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 14
... Section D.1 INTERNAL PROFILE OF THE EXHAUST DUCT Templates of the internal dimensions of the exhaust duct: gasket plane of the manifold. FRONT VIEW DRAWING with dimensions Minimum template Maximum template Measurement C must be minimum 15.5mm Measurement C must me maximum 16.5mm Maximum template: internal profile of the gasket plane of the manifold of the original cylinder plus 1 mm Minimum template: internal profile of the gasket plane of the manifold of the original cylinder minus 1 mm Thickness: 5 +/- 0,05 mm Technical Drawing No.13 bis Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 15
D.2 CONROD, CRANKCASE, CRANKSHAFT & PISTON EXPLODED DRAWING OF THE PISTON, CRANKSHAFT, CONNECTING ROD AND CRANKCASES UNIT (exploded crankshaft) Without screws or gaskets. The aim of the exploded drawings is to identify the principles, the functioning and the whole mechanical unit Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 16
...Section D.2 PHOTO OF THE CRANKSHAFT & CONROD PHOTO OF THE CONROD DRAWING OF THE PISTON Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 17
...Section D.2 PHOTO OF THE INSIDE OF THE RH CRANKCASE PHOTO OF THE INSIDE OF THE LH CRANKCASE DRAWING OF THE CRANKSHAFT - CON ROD UNIT (DIMENSIONS incl. tolerances, big & small ends thickness, crank mass thickness & diameter ) Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 18
D.3 BALANCE SHAFT & WATER PUMP EXPLODED DRAWING OF THE BALANCE SHAFT, WATER PUMP INCLUDING HOUSING Without screws or gaskets. The aim of the exploded drawings is to identify the principles, the functioning and the whole mechanical unit Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 19
Section D.3 PHOTO OF THE BALANCE SHAFT PHOTO OF THE WATER PUMP IMPELLER DRAWING OF THE BALANCE SHAFT (DIMENSIONS incl. tolerances) Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 20
D.4 REED VALVE & CLUTCH TECHNICAL DRAWING (exploded view) OF THE CLUTCH ASSEMBLY TECHNICAL DRAWING (exploded view) OF THE REED VALVE The aim of the exploded drawings is to identify the principles, the functioning and the whole mechanical unit Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 21
Section D.4 DRAWING OF THE REED VALVE (DIMENSIONS incl. tolerances) DRAWING OF THE REED VALVE COVER (only basic engine) Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 22
D.5 EXHAUST SYSTEM PHOTO OF THE EXHAUST MANIFOLD Maximum inner diameter of exhaust socket is:- - 18.2mm (125 Micro Max) PHOTO OF THE EXHAUST Exhaust for 125 Micro Max TECHNICAL DESCRIPTIONS OF THE EXHAUST (Art. 8.9.3 of HR) Weight in g - MICRO MAX: 2300G Minimum Volume in cc +/-5 % Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 23
D.6 STARTER EXPLODED DRAWING OF THE STARTING UNIT AND OF ITS HOUSING Without screws or gaskets. The aim of the exploded drawings is to identify the principles, the functioning and the whole mechanical unit Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 24
D.7 ELECTRICAL SYSTEM IGNITION SYSTEM Ignition homologation No. Ignition homologation No. Ignition homologation No. Dellorto Ignition System Ignition Coil is labelled with two stickers BRP 666820 & NIG0105 Electronic box is labelled with sticker 666814, 125 MAX evo Code F125 --/M/18 Color yellow Copyright 2014 Karting Australia. All rights reserved. KA HOMOLOGATION NUMBER 110H 25
Appendix A to ROTAX MICRO MAX Homologation Documents The following notes are additional to the details contained in these Homologation documents for the ROTAX MICRO MAX engine (the Engine ) and are to be read in conjunction with the specifications and details contained therein. They form part of the Homologation documents for the Engine. The Engine must at all times be used and be presented in strict conformity with the specifications detailed in the homologation documents. Unless otherwise expressly permitted by Karting Australia, only Rotax OEM parts that have been manufactured and/or supplied by Rotax for the Engine are permitted to be used in the Engine at any time. Neither the Engine nor any of its ancillary components may be modified other than in accordance with the Rules, these Homologation and Technical Specification documents. UNLESS IN THE KARTING AUSTRALIA RULES AND/OR THESE HOMOLOGATION AND TECHNICAL SPECIFICATION DOCUMENTS IT SAYS THAT YOU CAN, THEN YOU CANNOT. FOR AUSTRALIAN COMPETITION GENERAL 1. EVO ENGINE INTRODUCTION INTO AUSTRALIAN KARTING The introduction of the Rotax EVO Engines into Australia will be separated into two distinct categories: a. Engines that are to be used in all Rotax Pro Tour National Series Competition Classes; and b. Engines that are to be used in non- Rotax Pro Tour Competition Classes including; KA TaG, Tag 125, TaG 125 Restricted, Junior Max, Rotax 125 and DD2. 2. NON EVO, UPGRADED TO EVO OR FULL EVO 2015 a. A FULL EVO 2015 ENGINE (EVO) is a complete new Rotax EVO Engine including exhaust system as homologated by KA in 2015 and that has been purchased from IKD after 1 January 2015. i. A FULL EVO 2015 ENGINE must use all of the EVO Components supplied save that it is permitted for an EVO Engine to use a cylinder head cover that is not red, and a crankcase that is not black. b. An UPGRADED TO EVO ENGINE (EVO) is a previously homologated Junior Max, Rotax 125 or DD2 engine ( Older Engines ) that has been wholly or partially upgraded to EVO Engine specification by the addition of any of the Performance Components listed herein. i. Note that for Rotax Pro Tour Competition, if any of the Performance Components are used on the Engine, all of the Performance Components must be used. ii. Note that for non- Rotax Pro Tour Competition, the Engine can be partially Upgraded to EVO Engine specification by the use of any of the Performance Components (in which case it will still be considered to be an Upgraded to EVO Engine ). AUSTRALIA - Version: 1 2 June 2015 Page: 1 of 36
iii. For the sake of absolute clarity, the EVO Exhaust System and EVO Exhaust Socket are not designated by Rotax or IKD to be Performance Components and are not required to be fitted to an Upgraded To EVO Engine. c. A NON EVO ENGINE (NON EVO) is a previously homologated Junior Max, Rotax 125 or DD2 engine ( Older Engines ) that has not been wholly or partially upgraded to EVO Engine specification by the addition of any of the Performance Components listed herein. i. A Non EVO Engine is permitted to use the EVO Exhaust System, EVO Exhaust Socket, EVO Conrod, EVO Crankshaft, EVO Piston and EVO Battery Holding Unit and Switches. 3. EVO PERFORMANCE COMPONENTS All EVO performance components are external only. EVO Performance Components are: a. Carburettor VHSB 34 XS (Rotax Part no. 295 060) b. Dellorto Ignition System with Electronic Box (Rotax part no. 666 812) Once an engine is determined to be either NON EVO, or EVO (Includes both UPGRADED TO EVO and Full EVO 2015 Engines) the relevant Technical Specifications outlined in this document apply to that Engine. 4. The introduction of the new Rotax EVO Engine to Australian competition will be done according to the following principles. 5. Rotax Pro Tour Events a. Rotax World Rules as approved by KA for Australia will apply to these events commencing at Rotax Pro Tour Round 4, 2015. b. EVO Engines will be permitted to be used in accordance with the homologation of these engines. c. Previously homologated Junior Max, Rotax 125 and DD2 engines (the Older Engines ) will remain eligible for competition in Rotax Pro Tour events. d. There will be no parity adjustments to equalize the EVO Engines and the Older Engines in the Rotax Pro Tour. e. Older Engines can be upgraded at any time to full EVO Engine specification using the EVO Performance Components. AUSTRALIA - Version: 1 2 June 2015 Page: 2 of 36
(A) FR 125 JUNIOR MAX (NON EVO) SPECIFICATION ONLY WITHIN THE ENGINE SEAL Squish Gap A1.1 A1.2 FR 125 Junior Max: Minimum = 2.4mm The squish gap must be measured with a certified slide gauge and by using a 3 mm tin wire (Rotax part no. 580 132). The crankshaft must be turned by hand slowly over top dead centre to squeeze the tin wire. The squish gap must be measured on the left and right side in the direction of the piston pin. The average value of the two measurements counts. Combustion A2.1 Cast identification code has to be "223 389" or Chamber "223 389 1" or "223 389 2" or 223 389 2/1" or Insert 223 389 2/2. A2.2 Casted wording "ROTAX" and/or "MADE IN AUSTRIA" must be shown A2.3 Heights of combustion chamber insert have to be 27.55 mm with a tolerance of +0.0/-0,1 mm (A) and 28.80 mm with a tolerance of +/- 0.2 mm (B). A2.4 The profile of the combustion chamber insert has to be checked with a template (ROTAX part no. 277 390). The crack of light between the template and the profile of the combustion chamber insert has to be the same over the whole profile. NOTE: If the combustion chamber insert fails the template check as described herein, detailed measurements of the combustion chamber insert must be taken to determine conformity or nonconformity of the component. Piston with Ring Assembly A3.1 A3.2 A3.3 Original, coated or uncoated, aluminium, cast piston with one piston ring. The piston has to show on the inside of the cast wording "MADE IN AUSTRIA" (Image 1) and "ELKO" (Image 2). Machined areas are: Top end of piston, outside diameter, groove for the piston ring, bore for the piston pin, inside diameter at bottom end of piston and some pre-existing factory removal (Image 3) of flashing at the cut out of the piston skirt. All other surfaces are not machined and have cast surface. Any mechanical treatment or rework of the piston is forbidden, (e.g. removal of carbon deposits). Cleaning without changing the original surface is allowed. AUSTRALIA - Version: 1 2 June 2015 Page: 3 of 36
A3.4 A3.5 Original, magnetic, rectangular piston ring. Ring height: 0,98 +/- 0,02 mm. Piston ring is marked either with "ROTAX 215 547" or "ROTAX 215 548". Piston Pin (Gudgeon Pin) A4.1 A4.2 A4.3 Piston pin is made out of magnetic steel. Dimensions must be according to the drawing. The minimum weight of the piston pin must not be lower than 32.10 grams. Cylinder A5.1 Light-alloy-cylinder with GILNISIL-plating. Any re-plating of cylinder is not allowed. A5.2 Cylinder with one main exhaust port and no exhaust valve. A5.3 Maximum bore of cylinder = 54,035mm (measured 10 mm above the exhaust port). A5.4 Cylinder has to be marked with the "ROTAX" logo (see pictures). A5.5.1 Cylinder has to be marked either identification code 223 998, 223 994 (see pictures). A5.5.2 Cylinder 223 999 is outlawed. A5.6 Height of cylinder has to be 87mm -0.05/+0.1mm (measured with a digital calliper). A5.7.1 All transfer ports and passages have cast finish surface except some removal (done by the manufacturer) of cast burr at the inlet passage, exhaust port and passages. All ports have chamfered edges to prevent ring snagging. Any additional machining is not permitted. The top AUSTRALIA - Version: 1 2 June 2015 Page: 4 of 36
edge of exhaust port may show some pre-existing machining from the manufacturer. The sealing flange for the exhaust socket may show signs of machining from the manufacturer. A5.7.2 All ports have chamfered edges. Any additional machining is not permitted. A5.7.3 On cylinders marked 223 994 the upper edge of the central boost port may show factory machining. A5.7.4 The flange for the exhaust socket may show either cast finish or machined surface. Machined surface can be either flat or show a circular sealing bump. A5.7.5 The top edge of the exhaust port may show either just a cast finish surface (Image1) or signs of CNC machining (Image2) or signs of CNC machining in combination with signs of manual grinding (Image 3). The exhaust port may show partial manual grinding done by the manufacturer to eliminate minor casting defects and/or to eliminate the NIKASIL burr at the end of the NIKASIL plating (Image 3). AUSTRALIA - Version: 1 2 June 2015 Page: 5 of 36
A5.7.6 On cylinders marked 223 994 the exhaust port may show factory machining all around. A5.8 FR 125 Junior Max: Cylinder 223 998 = 0.90 mm Cylinder 223 994 = 1.10 mm The "exhaust port timing" (distance from the top of the cylinder to the top of the exhaust port) has to be checked by means of the template (Rotax part no. 277 397). Insert the template into the cylinder, so that the template is touching the cylinder wall and that the finger of the template is located in the middle of the exhaust port (highest point). Move the template upwards, until the finger is touching the top edge of the exhaust port. Insert a filler gauge between the top of the cylinder and the template. It must not be possible to fit the feeler gauge specified below. NOTE: Take care to use the corresponding gauge of the template (JUN, MAX or DD2) for the respective cylinder. Inlet System A6.1 A6.2 Inlet manifold is marked with the name "ROTAX" and the identification code 267 915 Some factory flash removal may be present at the conjunction of the inside contour and the carburettor stop mounting face. This is a manual trimming operation consisting of a small corner break of less than 3 mm in width. No additional grinding or machining is permitted. A6.3 A6.4 The reed valve assy. is equipped with 2 petal stops and 2 reeds, each having 3 petals. The thickness of the reeds is 0.6 mm +/- 0.10 mm. AUSTRALIA - Version: 1 2 June 2015 Page: 6 of 36
Crankshaft A7.1 A7.2 A7.3 A7.4 Stroke 54.5 mm +/-0,1 mm Con rod has to show forged numbers "213", "365", "367" or 362 on shaft. Shafts of con rods "213", "365" and "367" are not machined and are copper plated (Image 1). Shaft of con rod 362 is not copper plated and blank/grey (Image 2). Grinding or polishing of shaft of con rod is not permitted. A7.5 Effective from 1st June 2012, crankshaft main bearing 6206 from FAG only is allowed for Rotax National Series, State Championships or events where Rotax is run as a standalone class (must be marked with code 579165BA or Z-579165.11.KL). This does not apply to Restricted TAG, TAG & Sportsman style classes. Balance Shaft A8.1 A8.2 Balance shaft and balance gears must be installed Configurations of part no. 237 949 (equal with 237 948) only is legal. A8.3 A8.4 A8.5 Surface (1) is not machined and must show cast surface. Measurement from centre of balance shaft to outer diameter of fly weight of balance shaft at defined length must not be lower than specified. The minimum weight of the dry balance shaft must not be lower than: 255 grams for balance shaft Rotax part no. 237 949 (equal with 237 948). Crankcase A9.1 A9.2 As supplied by the manufacturer. No grinding or polishing is permitted in the two main transfer passages as well as in the crank area. Uncoated as well as black coated crankcases are legal to be used. AUSTRALIA - Version: 1 2 June 2015 Page: 7 of 36
Balance Drive A10.1 A10.2 A10.3 A10.4 Only steel balance gears are legal to be used at Rotax National Series, State Championships or events where Rotax is run as a standalone class. Other events can continue to use the old style plastic balance gears. Balance gears must be installed and must be aligned according to the instruction in the repair manual. Mixing of steel balance gears of different width (6.0 and 9.0 mm) is strictly forbidden. Balance drive gear compartment must be vented and connected to a minimum 100mL plastic overflow bottle via plastic hose. (A) FR 125 JUNIOR MAX SPECIFICATION ONLY OUTSIDE THE ENGINE SEAL It is the responsibility of the competitor to check his equipment (all components outside the engine seal as mentioned below), to assure that his equipment is conforming to the technical specification below. DENSO A11.1 DENSO digital battery ignition, variable ignition Ignition timing, no adjustment necessary and possible. System A11.2 The casting of the ignition coil has to show the following in casting "129000-" and "DENSO" (Image 1). A11.3 Ignition coil must show 3 pins at the terminal (Image 2). A11.4 Connector housing of ignition coil must have either black or green colour. A11.5 The ignition coil has to be fixed by means of 2 original silent blocks to the gearbox cover. Only in case of chassis component interference with the original mounting location of the ignition coil, a supplementary extension bracket, rigidly constructed and fabricated of solid metal, of minimum dimensions and attached to the original case mounting holes, is permitted for mounting of the coil. A11.6 Minimum length of ignition wire (high tension wire) is 210 mm from outlet of cable at ignition coil to outlet of cable at spark plug connector (the visible length of wire). Ignition coil must be in working condition (to be tested in case of doubt). AUSTRALIA - Version: 1 2 June 2015 Page: 8 of 36
A11.7 The pick-up must be marked with the numbers 029600-0710, followed by a variable production code in the 2nd line (Image 3). HINT: In case of doubt, an easy check is to place a steel ball (3-5 mm in diameter) on the pick-up (engine side). The steel ball must stay in the center of the pick-up surface. A11.8 A11.9 A11.10 Spark plug cap must be marked with NGK TB05EMA (Image 4). Battery must be fitted to the chassis with at least 2 screws. Position of the battery is free. The earth strap may be fitted with a connector for ease of removal of the engine. Rotax Wiring Harness must be OEM only, with no fittings or repairs. The ignition coil can be relocated from the crankcase as far as the OEM harness will permit. Centrifugal A13.1 Dry centrifugal clutch with engagement maximum Clutch at 4,000 r.p.m. This means that the kart must start to move before the engine speed reaches 4,000 r.p.m. There are 2 versions of the steel clutch (Image 1) and both are legal to be used. The older version can be either untreated or nitrated configuration. A13.2.1 A13.2.2 Needle cage bearing 15x19x17 (Rotax part no. 632 415) must be fitted for 12, 13, 14 & 15 tooth sprockets. Plain bearing 15x17x20 (Rotax part no. 233 855) must be fitted for 11 tooth sprockets. (Image 2) O-Ring 12x2.5 (Rotax part no. 950 815) must be fitted and must assure an appropriate sealing between the clutch drum and the needle/plain bearing. A13.3 No extra lubrication or substance is allowed inside the clutch drum, in addition to the grease that originates from lubrication of the needle cage bearing, and enters the clutch area. See (Images) showing worst case scenario of when grease exits the needle bearing area, even with the O-Ring installed. Only the fixation nut and the inside of the drum show signs of grease. The running surface of the drum is completely dry. When the plain bearing for 11 tooth sprockets is used, the clutch area must be absolutely free of grease or any additional substance. AUSTRALIA - Version: 1 2 June 2015 Page: 9 of 36
A13.4.1 Steel clutch (both versions) and clutch drum must be within the following specifications: A13.4.2 Height of clutch: Minimum = 11.45 mm A13.4.3 Thickness of clutch: Minimum = 24.10 mm NOTE: Measurement has to be done at the 3 open ends of the clutch shoes, 5 10 mm from the machined groove (all clutch shoes must be completely closed at measurement, with no gap showing). A13.4.4 Outer diameter of clutch drum: Minimum diameter = 89.50 mm NOTE: Diameter has to be measured with a sliding calliper, just beside the radius from the shoulder (not at the open end of the clutch drum). A13.4.5 Inner diameter of clutch drum: Maximum diameter = 84.90 mm NOTE: The inner diameter has to be measured with a sliding calliper. The measurement has to be done in the middle of the clutch drum (in the contact area of the clutch drum). A13.4.6 Height of sprocket with clutch drum assembly: Minimum height = 33.90 mm A13.4.7 The original Rotax clutch (3 spring) is eligible to be used at any event until further notice. AUSTRALIA - Version: 1 2 June 2015 Page: 10 of 36
Intake Silencer A14.1 A14.2 A14.3 A14.4 A14.5 Intake silencer with integrated, washable air filter has to be used with all parts as shown in the illustration and has to be mounted on the support bracket with two screws (in dry and wet condition). Intake Silencer case bottom is marked on.the inside with the Rotax part no. 225 015 Intake Silencer case top is marked on the inside with the Rotax part no. 225 025. Air filter must be installed as shown in illustration. The original square type intake silencer is not eligible to be used for Rotax National Series, State Championships or events where Rotax is run as a standalone class. It can be used in Restricted TAG, TAG and Sportsman style classes. Carburettor A15.1 A15.2 A15.3 A15.4 A15.5 A15.6 A15.7 Dellorto carburettor with VHSB 34 cast in the housing of the carburettor. QD or QS is stamped in the housing of the carburettor. The complete inlet bore in the casting of the carburettor must show a cast surface. Carburettor Slide shows digits 40 in casting Jet needle stamped with K98 only. Settings of the carburettor adjustment screws are free. The following two combinations of floats and idle jets are legal: Combination 1: For carburettor insert 12.5 (as per illustration at rule 15.16.1) floats marked with 5.2gr must be used. Idle Jet and Idle Jet Insert stamped with the digits 30 must be used. Combination 2: For carburettor insert 8.5 (as per illustration at rule 15.16.1) floats marked with 3.6gr must be used. Idle Jet and Idle Jet Insert stamped with the digits 60 must be used. NOTE: Effective from 1 st January 2014, only Combination 2 is allowed for Rotax National Series, State Championships or events where Rotax is run as a standalone class. This does not apply to Restricted TAG, TAG and Sportsman style classes. AUSTRALIA - Version: 1 2 June 2015 Page: 11 of 36
A15.8 All jets must be correctly seated and securely fitted. A15.9 A minimum required size of Main Jet may be determined for each race event by a Supplementary Regulation. A15.10 Needle Valve assembly stamped with the digits 150 (Image 1) A15.11 Needle of Needle Valve marked with diamond symbol INC only (Image 2). A15.12 Start Jet is stamped with the digits 60. A15.13.1 Needle Jet is stamped with FN 266. A15.13.2 Total length of Needle Jet = 54.00 +/- 0.3 mm A15.13.3 Length of bottom section of Needle Jet = 11.50 +/- 0.2 mm A15.13.4 Top bore diameter of Needle Jet = 2.60 +/- 0.15 mm (measured 2mm inside) AUSTRALIA - Version: 1 2 June 2015 Page: 12 of 36
A15.13.5 4 x 4 cross holes diameter of Needle Jet: Plug gauge 0.90 mm may NOT enter one of the 16 cross holes of the Needle Jet. NOTE: Use jet gauge set (Rotax part no. 281 920) A15.14.1 A15.14.2 Idle Jet 30 and Idle Jet Insert 30 must be used with carburettor insert stamped 12.5, as per illustration at rule A15.16.1. Plug gauge 0.40 mm may NOT enter the bore of the Idle Jet 30. NOTE: Use jet gauge set (Rotax part no. 281 920) A15.14.3 Plug gauge 0.40 mm may NOT enter the bore of the Idle Jet Insert 30. NOTE: Use jet gauge set (Rotax part no. 281 920) A15.14.4 Plug gauge 0.40 mm may NOT enter one of the 4 cross bores of the Idle Jet Insert 30. NOTE: Use jet gauge set (Rotax part no. 281 920) A15.15.1 A15.15.2 Idle Jet 60 and Idle Jet Insert 60 must be used with carburettor insert stamped 8.5, as per illustration at rule A15.16.1. Plug gauge 0.65 mm may NOT enter the bore of the Idle Jet 60. NOTE: Use jet gauge set (Rotax part no. 281 920) A15.15.3 Plug gauge 0.65 mm may NOT enter the bore of the Idle Jet Insert 60. NOTE: Use jet gauge set (Rotax part no. 281 920) AUSTRALIA - Version: 1 2 June 2015 Page: 13 of 36
A15.15.4 Plug gauge 0.65 mm may NOT enter one of the 4 cross bores of the Idle Jet Insert 60. NOTE: Use jet gauge set (Rotax part no. 281 920) A15.16.1 Carburettor insert must show stamping of either 8.5 or 12.5, as illustrated. A15.16.2 Plug gauge 0.60 mm may NOT enter the angular bore of the 8.5 carburettor insert only. NOTE: Use jet gauge set (Rotax part no. 281 920) A15.16.3 Plug gauge 0.90 mm may NOT enter the vertical bore of the 8.5 carburettor insert only. NOTE: Use jet gauge set (Rotax part no. 281 920). A15.17.1 Remove atomizer from the carburettor body using the Venturi Tool Set (Rotax part no. 676 034). Total length of atomizer = 23.75 +/- 0.45 mm AUSTRALIA - Version: 1 2 June 2015 Page: 14 of 36
A15.17.2 Length of cylindrical part of atomizer = 15.75 +/- 0.25 mm A15.17.3 Dimension of cutaway of atomizer = 6.00 +/- 0.15 mm A15.17.4 Diameter of cross bore of atomizer = 4.05 +/- 0.15 mm A15.18 Optional carburettor plug screw marked ROTAX (Rotax part no. 261 030) is legal to be used. A15.19 The two vent fittings must be connected with the original 180mm air vent hose. (Rotax part no. 260 260). Fuel Pump A16.1 The original MIKUNI Fuel Pump (diaphragm type) must be used. Radiator A17.1 A17.2 A17.3 Single aluminium radiator, as shown in illustrations below. Radiator must be mounted on the right side of the engine, with all components as shown in the respective illustrations. No additional non-original cooling device is allowed. AUSTRALIA - Version: 1 2 June 2015 Page: 15 of 36
A17.4 A17.5 A17.6 The removal of the thermostat from the cylinder head cover is accepted. For versions 1, 2 and 3, tape can be applied around the radiator. Tape may not be removed from the radiator during operation on the track. All other means of air flow control through the radiator are prohibited, except for the plastic flap on version 3.For version 3, the removal of the original plastic flap is accepted. Version 1 Cooling area: Height = 290 mm, Width = 133 mm Thickness of radiator = 32 mm Version 2 Cooling area: Height = 290 mm, Width = 133 mm Thickness of radiator = 32 mm Version 2 has two legal options to mount the radiator to the retaining plate (see illustration). Version 3 Cooling area: Height = 290 mm, Width = 138 mm Thickness of radiator = 34 mm The word ROTAX is stamped on the side of radiator. Radiator Coolant A18.1 A18.2 Glycol base or soluble oil coolants are prohibited. Radiator coolant system must be fitted with a catch tank of minimum 100mL capacity to retain radiator coolant overflow, in accordance with Technical Rules Chapter1 Rule 9(h)(iii) 2 AUSTRALIA - Version: 1 2 June 2015 Page: 16 of 36
Exhaust A19.1 Must be as supplied by BRP-POWERTRAIN and System cannot be modified except for the replacement of the silencer absorption material and the use of threaded fasteners in place of the original rivets for securing the silencer end cap. A19.2 Just one piece of standard isolation mat is allowed to be used. Can only be replaced with genuine spare part (Rotax part no. 297 981). A19.3.1 A19.3.2 A19.3.3 Additional to the standard isolation mat is a special steel isolation mat which is legal, but not mandatory. It is to be fitted underneath the standard isolation mat, 10-12 mm from the end of the tube, with both clamps mandatory. Steel isolation mat dimension = 165 mm +10 mm Clamp (1) must be fitted at a distance of 18 +/- 2 mm from the end of the tube. Clamp (2) must be fitted at the end area of the steel isolation mat. A19.4 Exhaust pipe versions 1, 2 and 3 with after muffler as shown in illustrations are legal to be used. A19.5.1 Version 1 Tuned pipe and silencer are one piece. The silencer is welded to the 180 o elbow and the tuned pipe (Image 1). A19.5.2 A19.5.3 A19.5.4 A19.5.5 Diameter of hole of end cap Maximum = 21.0 mm Length of inlet cone = 592 mm +/- 5 mm (measured on outside from beginning of exhaust pipe until beginning of cylindrical part). Length of end cone = 225 mm +/- 5 mm Outside diameter of 180 o bent tube = 41 mm + 1.5mm / -1.0 mm (measure at beginning and end of bend). A19.6.1 Version 2 Tuned pipe and silencer are one piece. The silence is welded to the 180 o elbow. Two springs fix the silencer to the tuned pipe (Image 2). A19.6.2 A19.6.3 A19.6.4 Diameter of hole of end cap Maximum = 21.0 mm Length of inlet cone = 592 mm +/- 5 mm (measured on outside from beginning of exhaust pipe until beginning of cylindrical part). Length of end cone = 225 mm +/- 5 mm AUSTRALIA - Version: 1 2 June 2015 Page: 17 of 36
A19.6.5 Outside diameter of 180 o bent tube = 41 mm + 1.5mm / -1.0 mm (measure at beginning and end of bend). A19.7.1 Version 3 The tuned pipe with 180 o elbow and silencer are two separate pieces. The silencer is fixed with two springs to the 180 o elbow and two springs to the tuned pipe. A19.7.2 The silencer can be rotated so that the 90 o elbow outlet of the silencer is pointing either downward towards the asphalt (preferred for lowest noise emissions) or upward towards the back. A19.8 For measuring the exhaust gas temperature, a weld on a socket on top of the exhaust, 50 mm from the ball joint is allowed. A20.1 Exhaust sockets version 1 and 2 are legal to be used. Version 1 Without gasket ring (Image 1) Version 2 With gasket ring (Image 2) Measurement (C) must be at least 15.5 mm A20.2 The maximum use of exhaust springs to fix the exhaust to the cylinder is 4 springs. AUSTRALIA - Version: 1 2 June 2015 Page: 18 of 36
(B) 125 JUNIOR MAX EVO SPECIFICATION ONLY WITHIN THE ENGINE SEAL Squish Gap B1.1 B1.2 125 Junior Max EVO: Minimum 2.4mm The squish gap must be measured with a certified slide gauge and by using a 3 mm tin wire (Rotax part no. 580 132). The crankshaft must be turned by hand slowly over top dead centre to squeeze the tin wire. The squish gap must be measured on the left and right side in the direction of the piston pin. The average value of the two measurements counts. Combustion B2.1 Cast identification code has to be "223 389" or Chamber "223 389 1" or "223 389 2" or 223 389 2/1" or Insert 223 389 2/2. B2.2 Casted wording "ROTAX" and/or "MADE IN AUSTRIA" must be shown B2.3 Heights of combustion chamber insert have to be 27.55 mm with a tolerance of +0.0/-0,1 mm (A) and 28.80 mm with a tolerance of +/- 0.2 mm (B). B2.4 The profile of the combustion chamber insert has to be checked with a template (ROTAX part no. 277 390). The crack of light between the template and the profile of the combustion chamber insert has to be the same over the whole profile. NOTE: If the combustion chamber insert fails the template check as described herein, detailed measurements of the combustion chamber insert must be taken to determine conformity or nonconformity of the component. Piston with Ring Assembly B3.1 B3.2 B3.3 Original, coated or uncoated, aluminium, cast piston with one piston ring. The piston has to show on the inside of the cast wording "MADE IN AUSTRIA" (Image 1) and "ELKO" (Image 2). Machined areas are: Top end of piston, outside diameter, groove for the piston ring, bore for the piston pin, inside diameter at bottom end of piston and some pre-existing factory removal (Image 3) of flashing at the cut out of the piston skirt. All other surfaces are not machined and have cast surface. Any mechanical treatment or rework of the piston is forbidden, (e.g. removal of carbon deposits). Cleaning without changing the original surface is allowed. AUSTRALIA - Version: 1 2 June 2015 Page: 19 of 36
B3.4 B3.5 Original, magnetic, rectangular piston ring. Ring height: 0,98 +/- 0,02 mm. Piston ring is marked either with "ROTAX 215 547" or "ROTAX 215 548". Piston Pin (Gudgeon Pin) B4.1 B4.2 B4.3 Piston pin is made out of magnetic steel. Dimensions must be according to the drawing. The minimum weight of the piston pin must not be lower than 32.10 grams. Cylinder B5.1 Light-alloy-cylinder with GILNISIL-plating. Any re-plating of cylinder is not allowed. B5.2 Cylinder with one main exhaust port and no exhaust valve. B5.3 Maximum bore of cylinder = 54,035mm (measured 10 mm above the exhaust port). B5.4 Cylinder has to be marked with the "ROTAX" logo (see pictures). B5.5.1 Cylinder has to be marked either identification code 223 998, 223 994 (see pictures). B5.5.2 Cylinder 223 999 is outlawed. B5.6 Height of cylinder has to be 87mm -0.05/+0.1mm (measured with a digital calliper). AUSTRALIA - Version: 1 2 June 2015 Page: 20 of 36
B5.7.1 All transfer ports and passages have cast finish surface except some removal (done by the manufacturer) of cast burr at the inlet passage, exhaust port and passages. All ports have chamfered edges to prevent ring snagging. Any additional machining is not permitted. The top edge of exhaust port may show some pre-existing machining from the manufacturer. The sealing flange for the exhaust socket may show signs of machining from the manufacturer. B5.7.2 All ports have chamfered edges. Any additional machining is not permitted. B5.7.3 On cylinders marked 223 994 the upper edge of the central boost port may show factory machining. B5.7.4 The sealing flange for the exhaust socket may show either cast finish or machined surface. Machined surface can be either flat or show a circular sealing bump. B5.7.5 The top edge of the exhaust port may show either just a cast finish surface (Image1) or signs of CNC machining (Image2) or signs of CNC machining in combination with signs of manual grinding (Image 3). The exhaust port may show partial manual grinding done by the manufacturer to eliminate minor casting defects and/or to eliminate the NIKASIL burr at the end of the NIKASIL plating (Image 3). AUSTRALIA - Version: 1 2 June 2015 Page: 21 of 36
B5.7.6 On cylinders marked 223 994 the exhaust port may show factory machining all around. B5.8 FR 125 Junior Max: Cylinder 223 998 = 0.90 mm Cylinder 223 994 = 1.10 mm The "exhaust port timing" (distance from the top of the cylinder to the top of the exhaust port) has to be checked by means of the template (Rotax part no. 277 397). Insert the template into the cylinder, so that the template is touching the cylinder wall and that the finger of the template is located in the middle of the exhaust port (highest point). Move the template upwards, until the finger is touching the top edge of the exhaust port. Insert a filler gauge between the top of the cylinder and the template. It must not be possible to fit the feeler gauge specified below. NOTE: Take care to use the corresponding gauge of the template (JUN, MAX or DD2) for the respective cylinder. Inlet System B6.1 B6.2 Inlet manifold is marked with the name "ROTAX" and the identification code 267 915 Some factory flash removal may be present at the conjunction of the inside contour and the carburettor stop mounting face. This is a manual trimming operation consisting of a small corner break of less than 3 mm in width. No additional grinding or machining is permitted. B6.3 B6.4 The reed valve assy. is equipped with 2 petal stops and 2 reeds, each having 3 petals. The thickness of the reeds is 0.6 mm +/- 0.10 mm. AUSTRALIA - Version: 1 2 June 2015 Page: 22 of 36
Crankshaft B7.1 B7.2 B7.3 B7.4 Stroke 54.5 mm +/-0,1 mm Con rod has to show forged numbers "213", "365", "367" or 362 on shaft. Shafts of con rods "213", "365" and "367" are not machined and are copper plated (Image 1). Shaft of con rod 362 is not copper plated and blank/grey (Image 2). Grinding or polishing of shaft of con rod is not permitted. B7.5 Effective from 1st June 2012, crankshaft main bearing 6206 from FAG only is allowed for Rotax National Series, State Championships or events where Rotax is run as a standalone class (must be marked with code 579165BA or Z-579165.11.KL). This does not apply to Restricted TAG, TAG & Sportsman style classes. Balance Shaft B8.1 B8.2 Balance shaft and balance gears must be installed Configurations of part no. 237 949 (equal with 237 948) only is legal. B8.3 B8.4 B8.5 Surface (1) is not machined and must show cast surface. Measurement from centre of balance shaft to outer diameter of fly weight of balance shaft at defined length must not be lower than specified. The minimum weight of the dry balance shaft must not be lower than: 255 grams for balance shaft Rotax part no. 237 949 (equal with 237 948). Crankcase B9.1 B9.2 As supplied by the manufacturer. No grinding or polishing is permitted in the two main transfer passages as well as in the crank area. Uncoated as well as black coated crankcases are legal to be used. AUSTRALIA - Version: 1 2 June 2015 Page: 23 of 36
Balance Drive B10.1 B10.2 B10.3 B10.4 Only steel balance gears are legal to be used at Rotax National Series, State Championships or events where Rotax is run as a standalone class. Other events can continue to use the old style plastic balance gears. Balance gears must be installed and must be aligned according to the instruction in the repair manual. Mixing of steel balance gears of different width (6.0 and 9.0 mm) is strictly forbidden. Balance drive gear compartment must be vented and connected to a minimum 100mL plastic overflow bottle via plastic hose. (B) 125 JUNIOR MAX EVO SPECIFICATION ONLY OUTSIDE THE ENGINE SEAL It is the responsibility of the competitor to check his equipment (all components outside the engine seal as mentioned below), to assure that his equipment is conforming to the technical specification below. Dellorto B11.1 Ignition Coil (same for all engine types) with Ignition separate Electronic Box (ECU, specific to the System engine type). B11.2 Ignition coil and electronic box have to be fitted by means of the corresponding brackets and components according to the illustration. B11.3.1 B11.3.2 The visual appearance of the ignition coil must be identical with the pictures. Ignition coil must show 2 pins at the terminal. B11.3.3 B11.3.4 B11.3.5 The ignition coil is labelled with two stickers BRP 666820 and NIG 0105. The ignition coil is still legal to be used also if one or both stickers have disappeared. Minimum length of ignition wire (high tension wire) is 210 mm from outlet of cable at ignition coil to outlet of cable at spark plug connector (the visible length of wire). B11.3.6 The earth strap may be fitted with a connector for ease of removal of the engine. Rotax Wiring Harness must be OEM only, with no fittings or repairs. AUSTRALIA - Version: 1 2 June 2015 Page: 24 of 36
B11.4 The pick-up must be marked with the numbers 029600-0710, followed by a variable production code in the 2nd line (Image 3). HINT: In case of doubt, an easy check is to place a steel ball (3-5 mm in diameter) on the pick-up (engine side). The steel ball must stay in the center of the pick-up surface. B11.5 Spark plug cap must be marked with NGK TB05EMA (Image 4). B11.6.1 The electronic boxes are labelled with stickers (specific to the engine type) and are still legal to be used also if the sticker has disappeared. 125 Junior Max EVO: 666812 and 125 Junior MAX evo B11.6.2 The electronic box has to be checked with the ECU tester (Rotax part no. 276 230) according to the following procedure: 1. Disconnect engine cable harness from electronic box. 2. Connect ECU tester cable harness to electronic box. 3. Connect energy cable of ECU tester cable harness with the chargin connector of engine cable harness. 4. The ECU tester will automatically detect the type of the ECU and will start a check program for the ignition timing and the timing for the exhaust valve. 5. The ECU tester must show the following results for 125 Junior Max EVO: ECU TEST OK 125 Junior MAX evo Centrifugal Clutch B13.1 B13.2.1 Dry centrifugal clutch with engagement maximum at 4,000 r.p.m. This means that the kart must start to move before the engine speed reaches 4,000 r.p.m. There are 2 versions of the steel clutch (Image 1) and both are legal to be used. The older version can be either untreated or nitrated configuration. Needle cage bearing 15x19x17 (Rotax part no. 632 415) must be fitted for 12, 13 and 14 tooth sprockets. Plain bearing 15x17x20 (Rotax part no. 233 855) must be fitted for 11 tooth sprockets. (Image 2) AUSTRALIA - Version: 1 2 June 2015 Page: 25 of 36
B13.2.2 O-Ring 12x2.5 (Rotax part no. 950 815) must be fitted and must assure an appropriate sealing between the clutch drum and the needle/plain bearing. B13.3 No extra lubrication or substance is allowed inside the clutch drum, in addition to the grease that originates from lubrication of the needle cage bearing, and enters the clutch area. See (Images) showing worst case scenario of when grease exits the needle bearing area, even with the O-Ring installed. Only the fixation nut and the inside of the drum show signs of grease. The running surface of the drum is completely dry. When the plain bearing for 11 tooth sprockets is used, the clutch area must be absolutely free of grease or any additional substance. B13.4.1 Steel clutch (both versions) and clutch drum must be within the following specifications: B13.4.2 Height of clutch: Minimum = 11.45 mm B13.4.3 Thickness of clutch: Minimum = 24.10 mm NOTE: Measurement has to be done at the 3 open ends of the clutch shoes, 5 10 mm from the machined groove (all clutch shoes must be completely closed at measurement, with no gap showing). B13.4.4 Outer diameter of clutch drum: Minimum diameter = 89.50 mm NOTE: Diameter has to be measured with a sliding calliper, just beside the radius from the shoulder (not at the open end of the clutch drum). B13.4.5 Inner diameter of clutch drum: Maximum diameter = 84.90 mm NOTE: The inner diameter has to be measured with a sliding calliper. The measrement has to be done in the middle of the clutch drum (in the contact area of the clutch drum). AUSTRALIA - Version: 1 2 June 2015 Page: 26 of 36
B13.4.6 Height of sprocket with clutch drum assembly: Minimum height = 33.90 mm B13.4.7 The original Rotax clutch (3 spring) is eligible to be used at any event until further notice. Intake Silencer B14.1 Intake silencer with integrated, washable air filter has to be used with all parts as shown in the illustration and has to be mounted on the support bracket with two screws (in dry and wet condition). B14.2 B14.3 B14.4 B14.5 Intake Silencer case bottom is marked on.the inside with the Rotax part no. 225 015 Intake Silencer case top is marked on the inside with the Rotax part no. 225 025. Air filter must be installed as shown in illustration. The original square type intake silencer is not eligible to be used for Rotax National Series, State Championships or events where Rotax is run as a standalone class. It can be used in Restricted TAG, TAG and Sportsman style classes. Carburettor B15.1 B15.2 B15.3 B15.4 B15.5 B15.6 Dellorto carburettor with VHSB 34 cast in the housing of the carburettor. XS is stamped in the housing of the carburettor. The complete inlet bore in the casting of the carburettor must show a cast surface. Jet needle stamped with K57 only. Settings of the carburettor adjustment screws are free. The only combination of floats and idle jets that are legal is: Carburettor insert 12.5 (as per illustration at rule B15.15.1) floats marked with 4.0gr must be used. Idle Jet stamped with the digits 60 and Idle Jet Insert stamped with digits 45 must be used. AUSTRALIA - Version: 1 2 June 2015 Page: 27 of 36
B15.7 All jets must be correctly seated and securely fitted. B15.8 A minimum required size of Main Jet may be determined for each race event by a Supplementary Regulation. B15.9 Needle Valve assembly stamped with the digits 150 (Image 1) B15.10 Needle of Needle Valve marked with diamond symbol INC only (Image 2). B15.11 Start Jet is stamped with the digits 60. B15.12.1 Needle Jet is stamped with DP 267. B15.12.2 Total length of Needle Jet = 51.00 +/- 0.3 mm B15.12.3 Length of bottom section of Needle Jet = 33.0 +/- 0.2 mm B15.13.1 Idle Jet 60 and Idle Jet Insert 45 must be used with carburettor insert stamped 12.5, as per illustration at rule B15.15.1. B15.13.2 Plug gauge 0.65 mm may NOT enter the bore of the Idle Jet 60. NOTE: Use jet gauge set (Rotax part no. 281 920) B15.13.3 Plug gauge 0.55 mm may NOT enter the bore of the Idle Jet Insert 45. NOTE: Use jet gauge set (Rotax part no. 281 920) AUSTRALIA - Version: 1 2 June 2015 Page: 28 of 36
B15.13.4 Plug gauge 0.55 mm may NOT enter one of the 4 cross bores of the Idle Jet Insert 45. NOTE: Use jet gauge set (Rotax part no. 281 920) B15.14 Carburettor insert must show stamping of 12.5, as illustrated. B15.15.1 Remove atomizer from the carburettor body using the Venturi Tool Set (Rotax part no. 676 034). Total length of atomizer = 23.75 +/- 0.45 mm B15.15.2 Length of cylindrical part of atomizer = 15.75 +/- 0.25 mm B15.15.3 Dimension of cutaway of atomizer = 5.75 +/- 0.15 mm AUSTRALIA - Version: 1 2 June 2015 Page: 29 of 36
B15.15.4 Diameter of cross bore of atomizer = 5.00 +/- 0.15 mm B15.16.1 Optional carburettor plug screw marked ROTAX (Rotax part no. 261 030) is legal to be used. B15.16.2 The two vent fittings must be connected with the original 180mm air vent hose. (Rotax part no. 260 260). Fuel Pump B16.1 The original MIKUNI Fuel Pump (diaphragm type) must be used. Radiator B17.1 B17.2 B17.3 B17.4 B17.5 Single aluminium radiator, as shown in illustrations below. Radiator must be mounted on the right side of the engine, with all components as shown in the respective illustrations. No additional non-original cooling device is allowed. The removal of the thermostat from the cylinder head cover is accepted. For versions 1, 2 and 3, tape can be applied around the radiator. Tape may not be removed from the radiator during operation on the track. All other means of air flow control through the radiator are prohibited, except for the plastic flap on version 3.For version 3, the removal of the original plastic flap is accepted. B17.6 Version 1 Cooling area: Height = 290 mm, Width = 133 mm Thickness of radiator = 32 mm AUSTRALIA - Version: 1 2 June 2015 Page: 30 of 36
Version 2 Cooling area: Height = 290 mm, Width = 133 mm Thickness of radiator = 32 mm Version 2 has two legal options to mount the radiator to the retaining plate (see illustration). Version 3 Cooling area: Height = 290 mm, Width = 138 mm Thickness of radiator = 34 mm The word ROTAX is stamped on the side of radiator. Radiator Coolant B18.1 B18.2 Glycol base or soluble oil coolants are prohibited. Radiator coolant system must be fitted with a catch tank of minimum 100mL capacity to retain radiator coolant overflow, in accordance with Technical Rules Chapter1 Rule 9(h)(iii) 2 Exhaust B19.1 Must be as supplied by BRP-POWERTRAIN and System cannot be modified except for the replacement of the silencer absorption material and the use of threaded fasteners in place of the original rivets for securing the silencer end cap. B19.2 Just one piece of standard isolation mat is allowed to be used. Can only be replaced with genuine spare part (Rotax part no. 297 981). B19.3.1 B19.3.2 B19.3.3 Additional to the standard isolation mat is a special steel isolation mat which is legal, but not mandatory. It is to be fitted underneath the standard isolation mat, 10-12 mm from the end of the tube, with both clamps mandatory. Steel isolation mat dimension = 165 mm +10 mm Clamp (1) must be fitted at a distance of 18 +/- 2 mm from the end of the tube. Clamp (2) must be fitted at the end area of the steel isolation mat. AUSTRALIA - Version: 1 2 June 2015 Page: 31 of 36
B19.4.1 B19.4.2 The only exhaust pipe legal to be used is the version where the 180 o elbow and silencer are two separate pieces. The silencer is fixed with two springs to the 180 o elbow and two springs to the tuned pipe (Image 1). The silencer can be rotated so that the 90 o elbow outlet of the silencer is pointing either downward towards the asphalt (preferred for lowest noise emissions) or upward towards the back. 1 B19.5 For measuring the exhaust gas temperature, a weld on a socket on top of the exhaust, 50 mm from the ball joint is allowed. B19.6 Exhaust socket with gasket ring only is legal to be used (Image 2). Measurement (C) must be at least 15.5 mm B19.7 The maximum use of exhaust springs to fix the exhaust to the cylinder is 4 springs. 2 AUSTRALIA - Version: 1 2 June 2015 Page: 32 of 36
Supplementary Rules specific for Micro MAX to be read in conjunction with KA Technical Rules for Junior Max Micro MAX Squish gap: a) 125 Micro MAX Minimum = 2.40mm b) To achieve the defined squish gap, a spacer (ROTAX part no. 626 420, same shape as a cylinder base gasket) with at least two cylinder base gaskets (one below the spacer and one above the spacer) must be used. The squish gap must be measured with a certified slide gauge and by using a 3 mm tin wire. The crankshaft must be turned by hand slowly over TDC (top dead center) to squeeze the tin wire. Recommended 3mm tin wire (ROTAX part no. 580 132). The squish gap must be measured on the left and right side in the direction of the piston pin. The average value of the two measurements counts. Ignition System: Only the Dellorto Ignition System is legal to be used. The electronic box is labeled with stickers and are still legal even if the stickers have disappeared. Sticker shows 666814, 125 MAX evo The ECU Tester has to show the following result: ECU TEST OK 125 MAX evo AUSTRALIA - Version: 1 2 June 2015 Page: 33 of 36
Radiator: a) A specific "Micro MAX" radiator (ROTAX part no. 295 924 or 295 923) must be used instead of the original radiator. b) Radiator must be mounted with all components similar to the illustration version 2 or 3 for the 125 MAX engine. (see item 9.7.8 of the technical regulations 2014). c) Cooling area: height = 280-300 mm width = 58-62 mm thickness of radiator = 30-34 mm Exhaust restrictor: Only Exhaust Socket with gasket ring is legal to be used. Diameter (A) must apply for the length (B) of at least 12mm. Maximum inner diameter (A) of exhaust socket is: 18.20mm The measurement (C) must be at least 18.5mm. AUSTRALIA - Version: 1 2 June 2015 Page: 34 of 36
Exhaust system: a) The specific "Micro MAX" exhaust system must be used instead of the original exhaust system (see illustration below). b) The inner diameter of the elbow outlet at the silencer end cover has to have a minimum measurement of 21mm. Cylinder: a) The cylinder (ROTAX part no. 223 994) must be cast with two Letters within a circle on the drive side, and not a number. b) Any combination of two Letters is acceptable. Photo is for illustration purposes only. AUSTRALIA - Version: 1 2 June 2015 Page: 35 of 36