D-400 engine
| D-400 series engine | |
|---|---|
 Restored Masport Iron Horse engine | |
| Overview | |
| Manufacturer | Outboard Marine Corporation (OMC) Lawn-Boy |
| Also called | Iron Horse |
| Production | 1954--1977 |
| Layout | |
| Configuration | Single-cylinder 2-stroke |
| Displacement | 108.99 cc (6.651 cu in)[1] |
| Cylinder bore | 60.325 mm (2.3750 in) |
| Piston stroke | 38.1 mm (1.50 in) |
| Cylinder block material | Aluminum |
| Cylinder head material | Aluminum |
| Compression ratio | 4.5:1 |
| Combustion | |
| Fuel system | Float carburetor |
| Fuel type | Petrol |
| Oil system | 16:1-32:1 pre-mixed fuel:oil mix |
| Cooling system | Air-cooled |
| Output | |
| Power output | 3.5 hp (2.6 kW)[1] |
| Chronology | |
| Successor | D-600 |
The D-400 series engine or the Iron Horse engine was a light-duty two-stroke engine used for powering lawnmowers produced from the 1950s to the late 1970s. D-400 engines were single-cylinder engines designed and manufactured by the Outboard Marine Corporation (OMC; Johnson and Evinrude) for Lawn-Boy[2] and Masport. The D-400 engines displaced 109 cc, generated 3.5 hp (2.6 kW) of power, and operated in the range of 2400-3300 RPM.[1][3]
Description[edit]
The engines have a distinctive rectangular cowling that has created a nickname of brick-top mowers. Another distinctive feature is the two-finger vertical recoil starter.[3] The kidney-shaped muffler and exhaust unit is mounted beneath the mowers' deck and gives the engine a small, low profile design when compared to the newer and more powerful lawnmower engines. The ignition system employs a magneto, points, and a condenser (capacitor) set-up with an unusual spark-advance system which utilised a weight on the crankshaft to adjust the spark-advance amount depending on engine speed. The sprung governor was also unusual with a throw-yoke which operated under the flywheel and was linked to the throttle. The carburetor was a float design and fed into a pair of reed valves.
In New Zealand and Australia, Masport also known in New Zealand as "Charlie Gamble" offered the D-400 engine on their Premier, Premier II, Rancher, Rotacut, and Tornado models.[4] In this Oceania market, the D-400 was called the Iron Horse engine.
References[edit]
- ^ a b c Lawn-Boy (1983). "Lawn-Boy Service Manual 1950--1983". Retrieved 2012-02-04.
- ^ "Lawn-Boy brand history". 2012. Archived from the original on 2012-02-13. Retrieved 2012-02-04.
- ^ a b "Lawn Boy Engine series". 2008. Retrieved 2012-02-04.
- ^ "Moving Up to Masport TV Commercial [sic] (1972)". 2011. Retrieved 2012-02-04.