Zenoah 38cc Gas Engine New. Code (E039)

The Zenoah 38cc (most famously known as the G38, G380PU, or ZG38) is one of the most historically significant, rugged, and enduring two-stroke gasoline engines in the history of large-scale RC modeling. Introduced in 1984 by the Japanese engineering firm Komatsu Zenoah, it helped pioneer the shift away from expensive glow-fuel (nitro) engines toward practical, ultra-reliable petrol power for giant-scale aircraft.

Unlike many modern RC engines designed from scratch for model use, the G38 belongs to a legendary family of industrial powerplants. Zenoah leveraged its decades of experience manufacturing commercial chainsaws, brush-cutters, and agricultural sprayers to adapt these heavy-duty architectures for the hobby market.
Because it was originally engineered to run for thousands of hours cutting wood or clearing brush, it brought a level of industrial reliability and bulletproof metallurgic quality that the modeling world had rarely seen.

Core Engineering Characteristics:

• Magneto Ignition System: The defining characteristic of the classic Zenoah 38cc is its CD Magneto ignition. It does not require an external battery pack to fire the spark plug. Turning the propeller spins a magnet past a coil, generating its own power. On forums like the Model Flying Forums, users note a point of consensus that early versions featured a black kill wire to safely earth the ignition, though some pilots clipped it to minimize radio interference on old AM/FM frequencies.
• AAC/Chrome Architecture: The engine features a hard-chromed cylinder bore and an exceptionally rigid die-cast crankcase.
• The “Weight-for-CG” Reality: At roughly 2 kg (4.4 lbs) all-up, the engine is remarkably heavy by today’s standards. However, as discussed widely by modelers on the Model Flying Forums, this weight was actually considered a massive benefit for scale warbirds (like Spitfires or AT-6 Texans) that inherently have short noses and need heavy ballast upfront to achieve a proper Center of Gravity (CG).

Technical Specifications:

Displacement 37.4 cc (2.28 cu. in.)
Bore x Stroke 38 mm x 33 mm
Weight ~2.0 kg (4.4 lbs) with stock magneto and muffler
Power Output ~2.6 hp @ 7,200 RPM
Carburetor Walbro WT-338 (diaphragm type with choke)
Practical RPM 2,100 – 9,500 RPM
Standard Propellers 18×10, 19×8, to 19×10 (ideal for high-Torq)

In 2007, Komatsu Zenoah’s outdoor power equipment and hobby engine division was acquired by the Husqvarna Group. While the market has shifted toward lighter, purpose-built RC engines (like DLE or OS Gas), thousands of Zenoah 38cc engines built over the last 40 years are still flying today—a testament to their near-indestructible design.