the ax 120 special has extended crank timing, which was intended to push rpm range upwards, the tech notes also recommend the higher flow muffler as well



NOTES FROM OUR TECH DEPARTMENT


This is the 120AX Special Ringed Aircraft Engine from O.S. Engines.

FEATURES: High performance two stroke engine designed for sport and scale models Compact size enables it to fit into most cowls Crankshaft port timing was modified to increase power at high RPM Velocity stack on carburetor adds acceleration at high RPM 0.1mm head gasket increases compression ratio for more power 1mm deeper machining to enlarge intake port for greater RPM Two year limited warranty through Hobby Services beginning at date of purchase


NOTES FROM OUR TECH DEPARTMENT


This is the 120AX Special Ringed Aircraft Engine from O.S. Engines.

FEATURES: High performance two stroke engine designed for sport and scale models Compact size enables it to fit into most cowls Crankshaft port timing was modified to increase power at high RPM Velocity stack on carburetor adds acceleration at high RPM 0.1mm head gasket increases compression ratio for more power 1mm deeper machining to enlarge intake port for greater RPM Two year limited warranty through Hobby Services beginning at date of purchase

INCLUDES: 120AX Special Ringed Aircraft Engine, #8 Glow Plug, 70D Carburetor with Velocity Stack, Instruction Manual, Prop Washer & Nut and Needle Valve Extension Set

REQUIRES: Fuel: Two-Stroke with 18% lubricant and 5-20% nitromethane Muffler: E-5020 "Power Box" Propeller: 15x10-12 or 16x8-10