JPX PUL 425
The JPX PUL 425, also called simply the JPX 425, is a French twin-cylinder, horizontally opposed, two-stroke aircraft engine.[1]
| JPX PUL 425 | |
|---|---|
![]()  | |
| Two JPX PUL 425s mounted on a Lazair 2 | |
| Type | Two-cylinder two-stroke engine | 
| National origin | France | 
| Manufacturer | JPX | 
| Produced | until the early 1990s | 

The engine was produced only until the company went out of business in the early 1990s. The company was re-formed but the engine remains out of production and unsupported for parts.[1]
Design and development
    
The engine has two cylinders in a horizontally opposed configuration, with cooling fins on the cylinders. The single ignition system uses a coil and points. Fuel is metered by a single Tillotson butterfly-type carburetor. Starting is by a recoil starter system with electric start as an option.[1]
The 425 has a redline rpm of 4600 and does not use a reduction drive. Its weight of just 38 lb (17 kg) gives the engine a high power-to-weight ratio.[1]
Applications
    
    
Specifications (425)
    
Data from Cliche[1]
General characteristics
- Type: twin-cylinder, two-stroke engine
 - Displacement: 424 cc (25.87 cu inches)
 - Dry weight: 38 lb (17 kg)
 
Components
- Fuel system: Tillotson butterfly-type carburetor
 - Oil system: premixed oil and fuel
 - Cooling system: air cooled
 
Performance
- Power output: 26 hp (19 kW) at 4600 rpm
 
References
    
- Cliche, Andre: Ultralight Aircraft Shopper's Guide 8th Edition, page G-4 Cybair Limited Publishing, 2001. ISBN 0-9680628-1-4
 
