The lightweight 37 kW option: a 550 cc four-cylinder boxer two-stroke with EFI, delivered at 21.6 kg including starter and generator — the same peak power as the XW996F flagship, 8.4 kg lighter, for airframes where every kilogram of powerplant matters.
Highlights
1.71 kW/kg installed — the high power-density pick of the piston family.
High-torque starter, ignition and a 500/1000/1600 W generator ship inside the 21.6 kg.
RS232 data stream reports rpm, throttle and cylinder head temperature to your flight computer; PWM throttle, 12–15 V ECU.
Applications
Heavy fixed-wing & large VTOL airframes · Weight-critical 37 kW integrations · OEM powertrain programs
Product Images
Full Specifications
| Item | Value | Evidence |
|---|---|---|
| Layout | Four-cylinder boxer, two-stroke, air-cooled (66 × 40 mm bore × stroke) | Manufacturer spec |
| Displacement | 550 cc | Manufacturer spec |
| Max power | 37 kW @7,500 rpm; speed range 1500–7500 rpm | Manufacturer spec |
| Weight | 21.6 kg incl. starter and generator | Manufacturer spec |
| Dimensions | 390×400×400 mm incl. exhaust and air filter | Manufacturer spec |
| Fuel system | Electronic fuel injection; reed-valve intake; external 12 V pump | Manufacturer spec |
| Throttle / monitoring | PWM throttle; ECU 12–15 V; RS232 (rpm, throttle, CHT) | Manufacturer spec |
| Ignition | DC-CDI, NGK BPMR6A, 0.5 mm gap | Manufacturer spec |
| Fuel | 92–95 RON gasoline with 40:1 fully synthetic mix | Manufacturer spec |
| Generator | Outer-rotor three-phase, 500 W / 1000 W / 1600 W options; 28–29 V @3,500 rpm, coaxial direct drive | Manufacturer spec |
| Starter | High-torque, 16–16.8 V (4S), 150–170 A peak | Manufacturer spec |
FAQ
How does it compare with the XW996F?
Same 37 kW peak, 8.4 kg lighter (21.6 kg vs 30 kg) — choose the 4TK66FD when installed weight dominates; the four-stroke 996F wins on fuel burn per hour.
Is the generator really included?
Yes — a 28 V coaxial direct-drive generator in 500 W / 1000 W / 1600 W ratings is inside the 21.6 kg figure.
Can my flight controller read engine data?
Yes — RS232 telemetry outputs rpm, throttle position and cylinder head temperature.