Carburetor engine
The fuel pump is bolted to the cylinder head. It is driven via a lever directly from the camshaft. It does not need to be removed to check the pump.
Warning! When removing the fuel pump, some fuel may leak out. Fuel vapors are toxic, so ensure good ventilation. Avoid contact with skin. Wear fuel-resistant gloves. Do not work near open flames! Keep a fire extinguisher handy!
Examination
1. Disconnect the fuel hose on the carburetor and connect it to the pressure gauge.
2. Disconnect the return fuel hose from the pump and plug the nipple on the pump with a plug. Secure the plug with a clamp. Plug the return fuel line with a clean bolt.
3. Ask an assistant to start the engine. When the starter is running, read the pressure gauge. The pressure when the starter is running should be 2.8-3.5 Bar (E1, EZ, E5: 2.0-3.0 Bar).
4. Remove the pressure gauge and lower the fuel hose into a measuring vessel (graduating cylinder).
5. Ask an assistant to start the engine. The pump should deliver 800 ml of fuel per minute at idle speed.
6. Remove the plug, connect the fuel lines and secure with clamps.
7. If the values during the test do not correspond to the required ones, the pump is faulty and must be replaced.
Removal
1. Loosen the hose clamps and disconnect fuel hoses "1" and "2". Plug the hoses with suitable clean bolts. Mark the hoses with adhesive tape.
Caution! When disconnecting the fuel lines, place a rag underneath to collect any leaking fuel.
2. Unscrew the mounting bolts and remove the fuel pump "3", gaskets and insulator.
Installation
1. Carefully remove any remaining sealing material from the sealing surface on the cylinder head and the insulator using a scraper.
(The article is copied from the resource: MazBook.ru)
2. Install the fuel pump with 2 new gaskets and insulator and tighten the mounting bolts with force 25 Nm.
3. Connect the fuel lines according to the markings and secure with hose clamps.
4. Start the engine and check the tightness of the fuel pump and connections.