This is the OS Engines 46AX .46 ABL glow engine, with 40G carburetor and included OS E3070 Muffler. As the replacement for the high-performance 46FX, it's no wonder that the .46 AX shares many of its features. The raw power. A remote needle valve. Mounting bolt patterns. A balanced "D"-cut crankshaft supported by dual bearings. CNC-machining for the piston and other parts. And the same exclusive ABL cylinder liner that has made FX reliability a byword. But all the same, the 46AX is a different ?and better ?engine. Why? Because times change and technology advances. And because O.S. uses the best of both to make a good engine a better engine. Features: Features the 46FX's durable ABL (Advanced Bimetallic Liner) plating, as well as a new design that automatically centers, levels and seats the head during re-replacement. Head snugs down with only four screws ?not six. Subtly tapered low-end needle eliminates surging at transition, ensuring exceptionally smooth, consistent throttle control from idle to top speed. Redesigned liner ports and a ball-milled inlet port minimize turbulence during fuel/air mixing, making combustion and power output more predictable. New high-speed needle bracket simplifies horizontal/vertical mounting ?and can be replaced in just minutes. Minimizes vibration-induced "creep" and re-sets with a ratchet spring on the high-speed needle and O-ring seals on both needles. A simple rotor guide screw replaces the throttle stop screw ?and eliminates spring-related movement. Includes a new low-noise E-3070 muffler and 2-year limited warranty protection. Includes a lock nut and longer crankshaft with more thread length, for better prop nut engagement and greater pilot safety. SPECIFICATIONS: Displacement: 0.455 cu in (7.5 cc) Bore: 0.866 in (22.0 mm) Stroke: 0.772 in (19.6 mm) Practical rpm: 2,000-17,000 Output: 1.65 hp @ 16,000 rpm Weight w/muffler: 17.2 oz (489 g) Includes: #A3 glow plug, E-3010 muffler Requires: glow fuel, prop Recommended Props: 10.5x6, 11x6-8, 12x6-7