O.S. FS-200 Surpass w/F-6010 Sil. (L-OS35940) The largest, single-cylinder four-stroke engine that O.S. has ever made draws on unrivalled experience in engine design. This powerful, high-torque engine can turn big propellers & has been created with both scale & sports-scale modellers in mind, its compact external

Dimensions making installation within tight cowlings a real joy. Fuelling is courtesy of a specially designed twin needle carburettor &, like all the latest Surpass series, the internals have been lavished with the engineering care that only O.S. can achieve; top-grade material selection, precision machining & surface finish. Specifications: Capacity: 1.98cu.in. (32.4cc) Bore: 1.5" (38mm) Stroke: 1.13" (28.6mm) Weight: 30.1oz (853g) (w/o silencer) Power Output: 3hp @ 9, 000rpm Propeller Range: 15 x 12"
- 14", 16 x 12"
- 14", 17 x 10"
- 13", 17 x 12"
- 13", 18 x 8"
- 12" Silencer: F-6010






...

O.S. FS-62V w/F-4050 Silencer (L-OS30600) The second engine in the new V series of O.S. four strokes is targeted at both sports & scale modellers alike. Like the FS-95V, the FS-62V has the same classic overall design that appeals to scale modellers that like their engines to remain in character with the model. The performance, on the other h&, is very much 21st Century & builds on the O.S. tradition of constant technological advancement with each new range. In the case of the V series, there is also a strong emphasis on value for your money. The carburettor remains as the twin-needle type for both power & throttle response & the Jet Stream generation silencer allows both flexibility of orientation as well as effective sound reduction. By sharing the same mounting bolt pattern as the FS-52 Surpass & FSa-56, mounting the FS-62V as a direct replacement is easy & convenient. The angled pushrod & valve layout allows a better shape of combustion chamber, providing better power & efficiency. The cylinder head is also made from a special alloy that is different to the crankcase to balance durability against reduced weight. Only O.S. goes into this kind of original design detail, separating O.S. quality & performance from those that just copy! Specification: Weight: 442g (15.59oz)s w/o Silencer Weight: 486g (17.14ozs) w/ Silencer Propeller Range: 12 x 6, 12 x 7, 13 x 6, 13 x 7, 14 x 6 Displacement: 10.11cc (0.617cu.in) Bore: 25.0mm (0.984in) Stroke: 20.6mm (0.81in) Power Output: 1.1PS @ 10000rpm Practical RPM: 2400
- 11000rpm
...

O.S. FS-95V w/F-5050 Silencer L-OS30900 The first in a completely new series of four stroke engines aimed squarlely at the sport & scale modeller. Stying is deliberately retro & in keeping with the style of the very first OS four strokes. The original FS-120 had twin rocker covers & so do many full size engines in older aircraft. But retro stying does not mean retro technology! The FS-95V is a sophisticated piece of kit, delivering strong power & torque & offers a cost effective alternative to the FSa-81. The 60P carburettor is a twin needle design for great throttle response & reliable idling. There is nothing worse than having your engine cough at the wrong time when you really need a reliable response. The FS-95V will give you that pice of mind & respond just when you want it. That is why so many discerning modellers choose OS time after time! There are many models designed for. 61 2-strokes/.91 4-strokes & the FS-95V was created with that in mind. She will fit in anywhere that an FS-91S does, so model compatibility is not an issue. The added benefit, is far better silencing from the new F-5050, baffled, twin chamber silencer with an O-ring seal between the cast sections & variable length header pipe. Flexibility of silencer outlet position is well suited to scale installations & there are a variety of optional header pipes too, that will cater for just about every model.OS has always been at the forefront of safety, & continued use of a lock nut system for the propeller retention on the FS-95V is proof of this. The new V series of OS four stroke engines is here & setting the industry standards yet again. Specification Weight:592g (20.9oz) ...

O.S. FS30 Surpass w/F-1020 Silencer (L-OS33000) The smallest in the O.S. four stroke range &, at only 9.56 oz, its also the worlds lightest production model four stroke. It has most of the features of the larger single cylinder O.S. four strokes, but it has its camshaft carried in bronze bushes
- backed up by a pair of spherical thrust bearings. Ideal for trainers, scale & sport models. Designed to be used with 9” x 6~7” to 10” x 6” props. Specification: Weight: 279g Propeller Range: 9x 6-7 10x 4 Displacement: 4.89cc 0.299cu. In. Bore: 19.5mm 0.767in. Stroke: 16.4mm 0.648in Practical RPM: 2500-13000
...

O.S. FSa-110 w/F-5040 Silencer (L-OS35410) Designed specifically to offer more power & torque compared to a. 91 size four stroke, yet still fit in the same mounting

Dimensions, the FSa-110 is a real compact powerhouse. Like all FSa series engines, the FSa-110 has near perfect carburation across the RPM range, & thanks to the carefully designed exhaust, a soft yet authoritive note to minimise your presence to the neighbours. Precision carburation, internal oil recirculation & dramatic styling are all features of the FSa range & put this & the other derivatives that cut above the opposition. Specification: Weight: 600g (672g w/silencer) Displacement: 18.0cc Bore: 30.4mm Stroke: 24.8mm Power Output: 1.8PS @ 10, 000RPMPractical RPM: 2, 000
- 11, 000


...

O.S. FSa-110 w/F-5040 Silencer (L-OS35410) Designed specifically to offer more power & torque compared to a. 91 size four stroke, yet still fit in the same mounting

Dimensions, the FSa-110 is a real compact powerhouse. Like all FSa series engines, the FSa-110 has near perfect carburation across the RPM range, & thanks to the carefully designed exhaust, a soft yet authoritive note to minimise your presence to the neighbours. Precision carburation, internal oil recirculation & dramatic styling are all features of the FSa range & put this & the other derivatives that cut above the opposition. Specification: Weight: 600g (672g w/silencer) Displacement: 18.0cc Bore: 30.4mm Stroke: 24.8mm Power Output: 1.8PS @ 10, 000RPMPractical RPM: 2, 000
- 11, 000


...

O.S. FSa-56 w/F-4040 Silencer (L-OS34300) The new FSa-56 from O.S. is the first engine in a completely new series of advanced four-strokes. The FS ‘ Alpha’ series draws on the experience gained from the Surpass range to develop & refine standards to a new level. The increased capacity compared to the FS-52 Surpass means more power/torque & the new carburettor provides even better throttle control across the entire RPM range! There are innovative features like incorporating the crankcase breather/oil recirculation system into the crankcase to dispense with external nipples & drain tubes as well as a dramatic & futuristic style. An effective & versatile silencer is supplied as standard. Specification Weight:419g/14.8oz w/o silencer Capacity:9.32cc / 0.569 cu.in. Propeller Range:13x 6-7 12x 6-8 13x 6 Silencer:F-4040 Bore:24.0mm / 0.945in Stroke:20.6mm / 0.811in Power Output:1.0PS @ 10, 000 RPM ...

O.S. FSa-72 w/F-5030 Silencer (L-OS34720) Sharing the same mounting

Dimensions as the old FL-70 & FS-70U, the new

...

O.S. FSa-81 w/F-5030 Silencer (L-OS34810) The new FSa-81 is a direct replacement for the FS-70 Surpass II, offering greater power & throttle precision in a compact & lightweight design. The crankcase mounting

Dimensions allow the FSa-81 to slot into the same mount that an FS -70S II would for an instant power upgrade. Like the FSa-56, the crankcase breather system has now been incorporated inside the engine to negate the need for an external vent & the excess oil that eminates from it. A propeller locknut assembly is of course standard. The new F-5030 silencer is very effective, thanks to its internal baffle & carefully matched internal volumes & opassages. The design allows a huge range of outlet positions to accomodate almost every model. Even the distance away from the engine can now be adjusted. The latest 60RA carburettor now features a constant velocity inlet for enhanced throttle response & reduced spitting. Specification: Weight: 556g 19.63oz Propeller Range: 13x 7-9, 14x 6-7 Silencer: F-5030 Displacement: 13.26cc 0.809 cu.in. Bore: 27.7mm 1.091in. Stroke: 22.0mm 0.866in. Power Output: 1.3PS @ 11, 000 Practical RPM: 2, 200
- 12, 000


...