Fuel injection pump for the Hahn & Sohn HDE 9300SS3 diesel generator

The fuel injection pump is the heart of the diesel engine's fuel system. The plunger, driven by the engine cam, pressurises the diesel fuel to the pressure required for atomisation in the combustion chamber and delivers it to the injector through the high-pressure pipe. The amount of fuel supplied is controlled by the speed governor via the control lever, allowing the engine to maintain a constant speed of 3000 rpm even under changing loads - in a generator, this is essential for maintaining a stable frequency of 50 Hz.

• This pump is supplied as an original replacement part for the Hahn & Sohn HDE 9300SS3 diesel generator with a single-cylinder, four-stroke, air-cooled 192F, 499 cm³ diesel engine. The pump body is made of cast iron, while the plunger and delivery valve are made of hardened steel - materials capable of withstanding continuous high-pressure loads.
• The assembly is supplied complete: pump body, plunger with return spring, delivery valve holder with high-pressure connection, control lever with ball joint for connecting the governor rod, and a mounting flange with two holes for attachment to the engine block. The connections are protected by plastic caps during delivery to prevent contamination. Version without electromagnetic valve (without solenoid for electrically stopping the engine).

Why customers choose it

• Original part specifically for the HDE 9300SS3 model - no uncertainty about compatibility
• Complete assembly including plunger, spring, delivery valve, and control lever
• Cast iron body and hardened steel internal components resistant to high pressure
• Connections protected by caps - the part arrives without contaminants in the fuel passages

Practical tip

The most common cause of problems is not the pump itself, but contaminated diesel fuel. Before replacing the pump, check the fuel filter, drain sediment from the tank, and make sure no air has entered the system - an engine that starts and then stops after a short time usually has air in the fuel lines rather than a faulty pump. If the engine cannot be started at all and no pressure can be detected at the high-pressure connection while cranking, the pump is likely to be the cause.

One rule takes priority over everything else during installation: not even a single particle of dirt must enter the fuel system. Remove the protective caps from the connections only immediately before connecting the pipes. It is advisable to keep a spare fuel injection pump available for generators used as backup power sources - without a functioning pump, the engine will not start and the generator will be completely unusable.

Key features

• Fuel injection pump for a single-cylinder diesel engine
• Designed for the Hahn & Sohn HDE 9300SS3 (192F engine, 499 cm³, 6-6.5 kW)
• Cast iron pump body
• Plunger with return spring
• Delivery valve holder with high-pressure connection
• Control lever with ball joint for the speed governor rod
• Mounting flange with two holes
• Fuel hose connection on the side of the body
• Version without electromagnetic valve (without solenoid)
• Connections protected by plastic caps

Use / Installation / Operation

Before replacement, switch off the engine, allow it to cool, and shut off the fuel supply. Disconnect the high-pressure pipe to the injector and the fuel supply hose, disconnect the governor rod from the control lever, and loosen the two flange bolts. During removal, note the position and number of shims beneath the flange - these determine the injection timing and must remain the same during installation.

Install the new pump with the same set of shims, tighten the flange bolts, and connect the governor rod. Remove the protective caps from the connections only immediately before connecting the pipes. After installation, the fuel system must be bled - loosen the nut on the high-pressure pipe at the injector, crank the engine with the starter until diesel fuel flows without bubbles, and then tighten the nut.

We recommend having the installation carried out by a service technician. Incorrect injection timing makes starting more difficult, increases fuel consumption, and may lead to engine damage.