Model Application: Ideal for 3D, Precision and Sport flying Mounting Application: Mounts in same space as the .91FX (actual mounting dimensions vary slightly, see SPECS) Internal Construction: Steel piston ring and liner, aluminum piston Muffler: E-5020 "Power Box" with extension and 90° adapters Carburetor: 70D with rearward angled needle valve for safety Glowplug: O.S. #8 supplied with engine, A5 (OSMG2693) will also work Warranty: Two-year limited INCLUDES: O.S. Max Two-Stroke 1.20AX Ringed Engine with E-5020 Power Box Muffler, #8 glow plug, muffler adapter, prop washer and lock nut, needle valve extension cable,instruction manual and decal sheet, two muffler screws, two muffler extension bolts, two long muffler SPECS: Displacement: 1.218 cu in (19.96cc) Bore: 1.197" (30.4mm) Stroke: 1.083" (27.5mm) Practical RPM: 1,800 - 9,500 RPM Power Output: 3.1ps/9000 RPM Weight of engine: 22.82oz (647g) without muffler,extension or adaptor Weight of muffler: 7.074oz (219.2g) with 90° adapter installed Weight of muffler: 7.907oz (245g) with extension installed Crankshaft thread size: 5/16-24 Distance Between Mounting Holes Same Side: 0.98" (25mm) Distance Between Mounting Holes Opposite Side: 2.3" (58mm) Distance Center of Crankcase to End of Crankshaft: 4.3" (109.5mm) Distance Center of Crankcase to Drive Hub: 2.7" (69.8mm) Width Between Mounting Tabs: 2.6" (67mm) Width of Crankcase Below Mounting Tabs: 1.8" (46.5) Length from Backplate to End of Crankshaft: 5.5" (139.9mm) Length from Backplate to Drive Hub: 3.9" (100.2mm) Height/Bottom of Crankcase to Top of Cylinder Head: 4.3" (109.2mm) Height/Bottom of Mounting Tabs/Top of Cylinder Head: 3.4" (85.7mm) Distance center to center of muffler mounting holes: 48mm (1.89") COMMENTS: For version without muffler, order OSMG0651. The version without the muffler does not include the muffler extension or the 90° adapter. At this time one would not be able to use the muffler extension and 90° adapter at the same time. The long muffler bolts are too long.