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. FS40 Surpass w/FS40S Silencer (L-OS35220) The original 6.5cc FS-40 was O.S.s second production single cylinder four stroke & the first to have the front mounted helical driven camshaft now common to all their single cylinder O.S. four stroke engines. The current FS-40S is an all-new design which is much more powerful & closely related to the FS-48, though smaller both internally & externally. Supplied complete with silencer, the FS-40S is ideal for sport & scale models & is designed for use with 10” x 7.5” to 12” x 6” propellers. Specification: Weight: 355g 12.52oz Propeller Range: 10x 7-7.5 11x 6 11x 7 12x 5-6 Displacement: 6.49cc 0.40cc. In. Bore: 21.20mm 0.835in. Stroke: 18.4mm 0.724in Power Output: 0.65PS@12000RPM Practical RPM: 2200-12000 ...

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-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


...