rotax junior max evo
MAIN JET (ON VP C9 RACE FUEL): 122 (120 IF AIR TEMP > 85 F / 29.5 C)
MAIN JET ON (93 PUMP FUEL W/ETHANOL): 125 (122 IF AIR TEMP >85 F / 29.5C)
MAIN JET NOTE: IF YOU ARE ON A 2016 OR OLDER CYLINDER, DROP ONE JET SIZE FROM THE ABOVE RECOMMENDATIONS
FUEL / OIL RATIO: 44:1 (2.9 OZ / GALLON) OR (22.7 ML / L)
PIN HEIGHT: PIN 4 (any leaner and your bottom end will really suffer, in cold conditions, go to pin 5)
FLOAT HEIGHT: NUETRAL (MIDPOINT ON ROTAX FLOAT TOOL)
AIR SCREW: 1.75 FULL TURNS OUT
IDLE SCREW: 4 FULL TURNS OUT (IDLE AROUND 2,500 RPM WHEN ENGINE IS COLD, SHOULD NOT REALLY IDLE WHEN HOT)
OPTIMAL WATER TEMP: 130 F / 54.5 C
SPARK PLUG: ROTAX GR9DI-8
SPARK PLUG GAP: .8 MM
UPGRADE FROM MINI:
PARTS: Senior header, Senior exhaust, Junior ECU, Senior radiator
ENGINE WORK: none required (same squish as Mini, 1.2mm)