Fuel pump — removal, inspection and installation

OHV engine fuel pump

OHV fuel pump elements

CVH engine fuel pump

Removing the fuel pump cover

On OHV engines, the fuel pump is mounted on the engine block and actuated by a lever from the camshaft eccentric.

On CVH engines, the fuel pump is mounted on the cylinder head and is actuated by a pushrod from the camshaft.

To remove the pump, disconnect the fuel hoses from the pump, plug them with plugs, and then unscrew the fastening nuts and remove the pump.

When installing the fuel pump on a CVH engine, check the pump's installation clearance.

Checking the installation clearance of the pump

1. Remove pushrod from cylinder head.

2. Clean mating surfaces.

3. Install the fuel pump without pusher and gasket and tighten the fastening nuts to a torque of 2–4 Nm.

4. Use a feeler gauge to measure the clearance between the pump flange and the head. If the gap is more than 0.25 mm, the fuel pump must be replaced.

Pump test

1. Remove the fuel supply line from the carburetor and place it in a container.

2. Disconnect the low voltage wire from the ignition coil and engage the starter. During normal operation of the pump, fuel will come out of the hose in bursts.

3. To clean the fuel pump, unscrew the mounting bolt.

4. Remove fuel pump cover (see fig. Removing the fuel pump cover).

5. Remove the mesh filter and clean it thoroughly.