Displacement: .213 cu in (3.49 cc)
Bore: .641 in (16.27 mm)
Stroke: .661 in (16.8 mm)
Practical RPM: 3,000-41,500
Power Output: 2.7 hp @ 34,000 rpm
Weight: 12.77 oz (362 g)
Includes: 2282 carburetor, 6 mm and 7 mm carb restrictors, P3 glow plug, exhaust seal and dust cap set
Requires: glow fuel, muffler, tuned pipe and manifold

The O.S. Engine 25FX II is a high performance side exhaust aero engine that is suitable for many styles of small R/C aircraft such as sport, scale, aerobatic and even .25 class pylon racers.

The 25FX II uses a direct needle 21L carburettor for excellent usability and a 892 silencer with adjustable exhaust direction.

Specification:
Weight: 260gr.
Capacity: 4.07cc
Bore: 18mm
Stroke: 16mm
Power Output: 0.84 ps (0.83 hp)
Practical RPM: 2,500 - 19,000

Specifications:
Displacement:10.63cc
Bore:24.0mm
Stroke:23.5mm
Practical RPM:2,500-16,000
Output:1.73hp/16,000rpm
Weight:497g

Included:
61D carburetor
E-4050 Muffler
#8 Glow Plug
needle Extention cable set.

Specifications:
Bore: 0.65 in (16.4 mm)    
Crankshaft Threads: UNF 1/4-28    
Cylinders: Single    
Displacement: 0.211 cu in (3.49 cc)    
HP: 2.61 hp @ 34,000 rpm    
Height: 3.32 in (84.3 mm)    
Length: 3.70 in (94 mm)   

Total Weight: 12.6 oz (356 g)    
Width: 1.77 in (45 mm)

Includes: P3 turbo plug, 5.8mm carb reducer installed, exhaust ring and tuned pipe set T-2090SC

Displacement: 0.213 cu in (3.49 cc)
Bore: 0.641 in (16.27 mm)
Stroke: 0.661 in (16.80 mm)
Practical rpm: 4,000-42,000
Power Output: 2.61 hp/2.65 ps @ 34,000 rpm
Weight: 12.45 oz (353 g)
Includes: Turbo P-3 plug

Displacement: 0.213 cu in (3.49 cc)
Bore: 0.641 in (16.27 mm)
Stroke: 0.661 in (16.80 mm)
Practical rpm: 4,000-42,000
Power Output: 2.61 hp/2.65 ps @ 34,000 rpm
Weight: 12.45 oz (353 g)

Includes: Turbo P-3 plug and O.S. T-2060SC Tuned Pipe With Manifold

Technical specifications:
- displacement 3.49cc
- bore 16.27mm
- stroke 16.80mm
- rpm 4000-42000 rpm
- max output 2.64hp/34000 rpm
- weight 347gr
- recommended exhaust T2100SC
- port 3-port

Technical specifications:
- displacement 3.49cc
- bore 16.27mm
- stroke 16.80mm
- rpm 4000-42000 rpm
- max output 2.64hp/34000 rpm
- weight 347gr
- recommended exhaust T2100SC
- port 3-port

Includes the OS T2100SC exhaust system

 Technical specifications:
- displacement 3.49cc
- bore 16.27mm
- stroke 16.80mm
- rpm 4000-42000 rpm
- max output 2.64hp/34000 rpm
- weight 354gr
- exhaust T2100SC
- port 5-port

Includes: Turbo P-3 plug
Requires: glow fuel, tuned pipe and manifold

 Technical specifications:
- displacement 3.49cc
- bore 16.27mm
- stroke 16.80mm
- rpm 4000-42000 rpm
- max output 2.64hp/34000 rpm
- weight 354gr
- exhaust T2100SC
- port 5-port

Includes: OS T2100SC exhaust system

O.S. Speed R21GT engine for the 1/8th GT on-road classes. Designed with the forthcoming 1/8th GT IFMAR World Championship in mind, the engine builds on the proven R2101 crankcase which was refined as was the 5+3 ports liner and piston to meet current IFMAR rules.

Tech specifications:
- Displacement: 3.49 cc
- Bore: 16.08mm
- Stroke: 17.20mm
- Intake ports: 5-port
- Exhaust port: 3-port

Combo of the O.S. Speed R21GT engine with the T-2060SC + MB01-70 (M2003SC) exhaust system for the 1/8th GT on-road classes.

Designed with the forthcoming 1/8th GT IFMAR World Championship in mind, the engine builds on the proven R2101 crankcase which was refined as was the 5+3 ports liner and piston to meet current IFMAR rules.

Tech specifications:
- Displacement: 3.49 cc
- Bore: 16.08mm
- Stroke: 17.20mm
- Intake ports: 5-port
- Exhaust port: 3-port

This is the competition nitro engine OS Speed B21 ADAM DRAKE EDITION II realized with the collaboration of Adam Drake.

Features:
- Designed according to Adam Drake\'s advice and taste.
-  New design cylinder liner with new porting.
- New design crankshaft with double tungsten counterweight
- New bore x stroke (see the attached specifications)
- Carburetor reducers are 6.5mm and 8.0mm to suit both powerful drive and fuel economy drive OS SPEED 5. P3 GOLD plug is used for more consistent idling.

Combo nitro engine OS Speed B21 ADAM DRAKE EDITION II with T-21000SC pipe realized with the collaboration of Adam Drake.

Features:
- Designed according to Adam Drake\'s advice and taste.
-  New design cylinder liner with new porting.
- New design crankshaft with double tungsten counterweight
- New bore x stroke (see the attached specifications)
- Carburetor reducers are 6.5mm and 8.0mm to suit both powerful drive and fuel economy drive OS SPEED 5. P3 GOLD plug is used for more consistent idling.

This is the O.S. Speed B21 Ronda Drake Edition competition engine. It’s very PINK and unique to complement her signature colors and style.   It’s an excellent choice for both buggy and truck racing as it provides a linear power band, exceptional fuel mileage and tons of overall power.

This is the O.S. Speed B21 Ronda Drake Edition competition engine. It’s very PINK and unique to complement her signature colors and style.   It’s an excellent choice for both buggy and truck racing as it provides a linear power band, exceptional fuel mileage and tons of overall power.

This combo comes with the 2100SC pipe and 75mm manifold. 

O.S. SPEED T1204 is the successor of T1203 which is the World Champion engine in 2018. T1204 has more toque in low-middle range with better performance. Two tungsten weights are embedded in the counterweight of newly designed crankshaft, which helps powerful performance in middle range.

Specifications:
Displacement 2.1cc
Bore: 13.67mm
Stroke: 14.30mm
Output 1.75ps - 1.73hp - 35.000r.p.m.
Practical rpm range: 5,000〜45,000r.p.m.
Weight:233g

Specifications:
- Displacement: 3.49 cc
- Bore: 16.27mm
- Stroke: 16.80mm
- Intake ports: 3-port
- Practical RPM range: 4,000 – 40,000 rpm
- Max. power output: 2.42 hp / 34,000 rpm
- Weight: 380Gr

O.S. SPEED B2104 engine. It is a long-stroke engine, bore x stroke is 16.27 x 16.80mm. It has quicker response in low range and more torque in middle range with consistent idling.Specifications:

- Displacement: 3.49cc / 0.213 cu.in.
- Bore: 16.27mm / 0.641 in.
- Stroke: 16.80mm / 0.661 in.
- Output: 2.68 ps / 2.64 hp / 34,000 r.p.m.
- Practical rpm range: 4,000-42,000 r.p.m.
- Weight: 352g / 12.42 oz.

Standard accessories:
- Glow plug T-P3 ・Reducer φ6Ⅱ、φ6.5Ⅱ・ Exhaust seal ring
- Dust cap set

O.S. SPEED B2104 Combo Set equipped with TB03 (T-2100, EFRA 2155) silencer with 80mm manifold (MB-01-80).

Specifications:
- Displacement: 3.49cc / 0.213 cu.in.
- Bore: 16.27mm / 0.641 in.
- Stroke: 16.80mm / 0.661 in.
- Output: 2.68 ps / 2.64 hp / 34,000 r.p.m.
- Practical rpm range: 4,000-42,000 r.p.m.
- Weight: 352g / 12.42 oz.

Standard accessories:
- Glow plug T-P3 ・Reducer φ6Ⅱ、φ6.5Ⅱ・ Exhaust seal ring
- Dust cap set