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 55AX w/E-3070 Silencer (L-OS15611) Designed to combine maximum power with razor-sharp throttle response in the smallest possible crankcase, the 55AX has the same mounting

Dimensions as the popular 46AX but with more power. The dramatic AX fin styling is used for optimum cooling, & the rearward-angled needle on the the type 40J carb makes for safer adjustments. Perfect for sport, scale & aerobatic appplications. Specification: Capacity: 0.54cu. in. (8.9cc) Bore: 0.91" (23mm) Stroke: 0.85" (21.5mm) Weight: 14.25oz (404g) (w/o silencer) Power Output: 1.75hp @ 16, 000rpm Practical RPM: 2, 000
- 17, 000 Propeller Range: 12 x 7"
- 8", 13 x 6"
- 7" Silencer: Power Box E-3070




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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-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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O.S. MAX 91HZ w/61E Carb Engine (L-OS18650) Identical in most techincal respects to the original Max 91HZ Ring engine but now with the latest 61E carburettor for an enhanced spread of power across the RPM range. Ideal for sports flying & F3C competition alike. You can rely on OS! ...

O.S. MAX 91HZ-PS Ring (L-OS18620) Designed primarily for the 3D flight & dramatic aerobatic manouevres. Compared to the old Hyper the new 91HZ-PS offers enhanced hovering stability as well as power at high speed to meet the further sophisticated 3D competition manouevres. A new design piston & crankshaft reduces vibration to provide further, stable torque over the entire RPM range. The rectangular heatsink head is completely included in the cooling shroud for better cooling. The black alumite finish with O.S. & 91HZ-PS logo impart a distinctive image. A Thermo insulator is installed on the carburetor mounting spigot & helps shut out engine heat to the carburettor, which in turn ensures a stable fuel/air mixture. The 91HZ-PS is equipped with a new, bigger capacity PD-08 pump & matched 61B-P carburettor plus integral regulator, which assures a consistent fuel supply irrespective of violent changes in model attitude. Combined with O.S. pump system, internal parts improvements same as the 91HZ contribute to stable power output & smoother higher engine performance. Specification: Weight: 635g Displacement: 14.95cc Bore: 27.7mm Stroke: 24.8mm Power Output: 3.5PS @ 15000RPMPractical RPM: 2000
- 16000
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