The Zenoah G260PUM is a compact 25.4 cm³ (1.55 cu in) 2-stroke petrol engine designed for high-RPM marine applications. It boasts a lightweight build and refined combustion design tailored for reliable power
 
Specifications
Displacement: 25.4 cc (bore 34 mm × stroke 28 mm)rcparts.co.nz+8mogatech.de+8gizmomotors.com+8
Power Output: 2.9 hp at around 12,000 rpm 
Torque: ~1.91 Nm at ~9,500 rpm (~1.52 ft‑lb)
Ignition: CDI magnetic system
Carburetor: Usually fitted with a Walbro WT‑644, featuring a manual choke; some units sold without carb
Fuel Mix: Typically 90-octane gasoline mixed 25:1 with 2‑stroke oil.
 
Physical Characteristics
Weight: Approximately 1.54–1.60 kg (3.4–3.5 lbs) depending on configuration
 
Dimensions (L×W×H): About 14.2 × 16.0 × 18.1 cm (5.6 × 6.3 × 7.1 in)
 
Design Highlights
Cylinder Design: Four-port 34 mm cylinder for enhanced airflow and torque at high RPMs
Piston: High-performance, lightweight steel or Cu-plated piston with a thin single-ring (≈1 mm) design for high rev capacity
Combustion Chamber: Redesigned "hemi‑style" chamber to improve thermal efficiency and power
Cooling: Water-cooled jacket suited for marine
 
Performance & Use
Rated up to 12,000–12,500 rpm, making it popular among RC boat racers
Tested output spans 2.16–2.32 kW (≈ 2.9–3.25 hp) depending on RPM and tuning
 
High torque curve (~9,500 rpm) for strong acceleration and load-handling
Maintenance & Upgrade Potential
Break-in Period: Gradual break-in recommended—run at lower RPM's.
 
Spare Parts & Kits: Replacement rings, gasket kits, piston upgrades, and cylinder porting kits are widely available.
 
Tuning Mods: Many aftermarket performance upgrades exist—ported top ends, lighter pistons, higher-duration exhaust porting—for racing configurations