OHV engine fuel pump
OHV Fuel Pump Components
1 – screw; 2 – lid; 3 – filter; 4 – sealing ring; 5 – pump
CVH Engine Fuel Pump
1 – mesh filter; 2 – lid
Removing the fuel pump cover
1 – fuel pump housing; 2 – sealing ring; 3 – screw; 4 – lid
On OHV engines, the fuel pump is mounted on the engine block and is driven by a lever from the camshaft eccentric.
On CVH engines, the fuel pump is mounted on the cylinder head and is driven by a tappet from the camshaft.
To remove the pump, disconnect the fuel hoses from the pump, plug them with plugs, then unscrew the mounting nuts and remove the pump.
When installing the fuel pump on the CVH engine, check the pump installation clearance.
Checking the pump installation clearance
1. Remove the tappet from the cylinder head.
2. Clean the mating surfaces.
3. Install the fuel pump without the pusher and gasket and tighten the mounting nuts to a torque of 2–4 Nm.
4. Use a feeler gauge to measure the gap between the pump flange and the head. If the gap is more than 0.25 mm, the fuel pump must be replaced.
Checking the pump
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 turn on the starter. When the pump is operating normally, fuel will flow from the hose in spurts.
3. To clean the fuel pump, unscrew the mounting bolt.
4. Remove the fuel pump cover (see Fig. Removing the fuel pump cover).
5. Remove the mesh filter and clean it thoroughly.