O.S. MAX 32SX-H Ring w/o Drive Wash Engine (L-OS12986) The ringed piston/liner assembly gives a lower compression on start-up without sacrificing top end power & performance, & provides easy needle setting characteristics. Developed for small helicopters, the O.S. MAX-32SX-H is a design suited to beginners & experts alike, who appreciate the quality. With many of the design features of the larger, F3C competition standard engines, the high performance 32SX-H has a new design of large bore carburettor
- type 20C
- to provide stable hovering characteristics & more power at the top end. It also

Includes:: a plated crankshaft to prevent corrosion & to increase the engines durability, a new rear ball bearing design with specially heat treated balls, enlarged con-rod & crank pin & a heat treated piston pin. With its ringed piston/liner assembly, twin ball raced crankshaft, enlarged cylinder head for enhanced cooling & mounting holes suited to most helicopters, the 32SX-H makes a worthwhile upgrade for any flyer. Specification: Weight: 285g (ring) 10.05 oz Displacement: 5.23cc 0.32cu in. Bore: 19.5mm 0.768in. Stroke: 17.5mm 0.689in Power Output: 1.2PS@18000 RPMPractical RPM: 2000-22000



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O.S. MAX 37SZ-H Ring w/o Drive Wash (L-OS14000) Following on from the concept developed in the 70SZ-H, the latest 37SZ-H brings a new level of performance to 30-class helicopters. Just about everything has been changed compared to the 32SX-H in the pursuit of power & control. That super-rigid crankcase contains a highly developed, ringed piston/liner set & optimised crankshaft for the right combination of power & smoothness. The new carburettor has been purpose designed for precision control & is capable of being operated by push-pull linkages if required. This is the perfect engine to compliment your new Hirobo Sceadu Evo & move your flying on to a new level. Specification: Weight: 293g 10.33 oz Displacement: 6.07cc 0.37cu in. Bore: 20.5mm 0.807in. Stroke: 18.4mm 0.724in Power Output: 1.4PS@18000 RPMPractical RPM: 2000-21000 ...

O.S. MAX 46AX w/E-3070 Silencer (L-OS15481) The first engine in the AX series, the 46AX features a new rear-mounted needle valve system that tolerates crash damage better. The new carburettor has been refined further to make adjustments more precise & throttling even more progressive. The amazing new P-Box silencer is both distinctive in styling as well as being functional. Inside, the ringless piston/liner system delivers strong power & enhanced life. ...

O.S. MAX 46LA Silv. w/E-3030 Silencer (L-OS13393) Physically identical to the popular 40LA but with a 20% increase in power & no discernible increase in weight. If youve built a model thats ended up a little on the heavy side for a 40LA then the 46LA could be the answer to your prayers! Like all engines in the LA range the 46LA comes with an A3 glowplug as standard plus the highly effective E-3030 Silencer. Specification: Weight: 272g (9.59oz) Propeller Range: 11x 6 11x 7 Displacement: 7.64cc (0.46cu.in.) Bore: 23.0mm (0.910in.) Stroke: 18.4mm (0.724in.) Power Output: 1.25PS@15000RPM Practical RPM: 2000~16000RPM ...

O.S. MAX 50SX-H Ring Hyper (L-OS15550) The best 50-class engine on the market just became amazing with the introduction of the new 50SX-H Hyper. That CNC machined cylinder head has been developed to give better power & enhanced cooling at the same time. The new carburettor has also been enhanced to help extract more power than the standard engine without sacrificing the throttle precision you have come to expect from OS helicopter engines. This truly is the best engine in the 50-class & is fast becoming the best seller as well. Its an OS, what else would you expect!! Specification: Weight: 413g Bore: 22.0mm 0.866in. Stroke: 19.6mm 0.772in Power Output: 1.8/17000 (BHP/RPM) Practical RPM: 2000-20000 ...

O.S. MAX 55HZ Hyper (L-OS15630) The max 50SX-H Hyper has established an enviable reputation for power, reliability & ease of use. The Max 55HZ Hyper moves that to a whole new level! Designed primarily with the demands of the 3D pilot in mind, the 55HZ Hyper delivers 61 size performance in a 46 size crankcase. That power comes from the extensive experience that OS has gained over many years & working extensively with the worlds top pilots to refine all aspects of the engine without compromise in any area. By using the same mounting layout, you can drop a 55HZ into any model that previously suited the 50SX-H without modification. Just the area around the new carburettor is a little bigger & may require adjustmenst to the cooling shroud. This entirely new engine shares almost nothing with the 50SX-H & has some new features not seen on an engine of this size before. The rear bearing is now designed to resist corrosion, the new 40L carburettor has three adjustments to cater for idle, mid range & full power. Until now, these features were the domain of 61 class engines or bigger. The throttle arm has four leaves so that push pull control is easy from any direction. The heatsink head is bigger for enhanced cooling as well. For the first time, OS is also offering a matching tuned muffler as an option part & has been optimised to extract the maximum performance from the 55HZ Hyper. Part number X-OS72144000. Specification: Weight: 408g (14.39oz) Displacement: 8.93cc (0.55cu.in) Bore: 23mm (0.91in) Stroke: 21.5mm (0.85in) Power Output: 2.1PS @ 17000RPMPractical RPM: 2000
- 20000
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O.S. MAX 55HZ Hyper Engine & Silencer
- Ltd. Ed w/ Pipe (L-OS15637) A special limited edition version of the fabulous Max
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O.S. MAX 55HZ-R Engine (L-OS15650) The latest engine in the 600/50 helicopter class borrows much of its technology from the fabulous Max 91HZ-R, to provide class leading power under the most demanding of 3D manouevres. The latest DRS system (Demand Regulator System) uses a crankcase pressure tap-off to pressurise the fuel tank via a one way valve. The pressurised fuel is then carfully regulated at the carburettor to provide the optimum mixture no matter what demands are placed on it. This is done by using the negative pressure in the carburettor venturi as part of the regulation system. The carburettor itself has three mixture controls for low/mid & high speed settings. Once set for the fuel demands of your model/type of fuel & muffler, there is rarely any need to change those settings again. The main mechanics of the engine itself are the same as the regulat Max 55HZ. Specification: Weight: 429g (15.13oz) Displacement: 8.93cc (0.55cu.in) Bore: 23mm (0.91") Stroke: 21.5mm (0.85") Power Output: 2.1PS @ 17000rpm Practical RPM: 2, 000
- 20, 000
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O.S. MAX 70SZ-H Ring Engine (L-OS17000) Developed directly from the feedback received from top FAI & 3D pilots throughout the world, the MAX 70SZ-H Ring produces copious quantities of power across the rev range without sacrificing its ability to perform precision hovering. Theres a stronger crankcase (with 6-point mounts), 3-needle carburettor & a revised liner/port design to give you the performance you need to beat the world! Particularly suited to the demands of 3D flight. Specification: Weight: 553.5g Displacement: 11.5cc 0.702cu. in Bore: 25.8mm 1.016in. Stroke: 22.0mm Power Output: 2.5/16000 (BHP/RPM) Practical RPM: 2000-18000 ...

O.S. MAX 75AX w/E-4040 Silencer (L-OS17400) The third engine in the new ‘AX’ range of high performance two-stroke engines fills a convenient gap between the existing 61FX & 91FX, yet features the radical new style pioneered with the fabulous 55AX. The new 75AX is supplied complete with the latest ‘P-Box’ design silencer for enhanced noise suppression. By keeping the lower crankcase

Dimensions the same as the 61FX, you can be sure that it will fit in all models designed for a. 61, making a power upgrade very simple. The 75AX features the latest O.S. ringless piston technology with multi-layer cylinder coating & high precision Type 61A carburettor with angled safety needle valve assembly. Specification Weight:578g / 20.39oz w/o silencer Capacity:12.29cc / 0.75 cu.in. Propeller Range:13x 8-10 14x 6-8 Bore:25.8mm / 1.016in Stroke:23.5mm / 0.925in Power Output:2.4PS @15, 000

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