Caution! Broken valve springs and damaged valve linings can be replaced without removing the cylinder head.
1. Remove the valve cover.
2. Unscrew the spark plug from the cylinder that has the damaged part. If you are replacing all the valve covers, you must unscrew all the spark plugs.
3. Turn the crankshaft so that the piston of the cylinder with the damaged part is at the top dead center. If you are replacing all the valve linings, start with the first cylinder and replace them one by one, according to the sequence of cylinder operation.
5.4 Adapter screwed into the spark plug hole
4. Screw the adapter into the spark plug hole (5.4) and connect the hose from the compressor to the adapter.
5.5 If you use the tool shown in the photo, it is not necessary to remove the intake valve rocker shaft
5. If you do not have a special lever tool (5.5), remove the rocker arm shaft.
6. Pump compressed air into the cylinder.
7. The valves should remain closed under air pressure. If the valve linings are in poor condition, air leakage will occur.
8. If you do not have a compressor, you can use an alternative method. Set the piston slightly below top dead center. Insert a nylon rope into the spark plug hole and push it in until it completely fills the combustion chamber. Turn the crankshaft until you feel slight resistance.
5.9 Remove the spring retainers using needle-nose pliers.
9. Plug the holes in the cylinder head with rags to prevent tools and parts from falling through. Compress the valve spring with a special tool. Remove the spring holders with pliers (5.9).
5.10 Remove the guide gasket with pliers.
10. Remove the spring support washer and the valve spring itself, then remove the guide gasket (5.10):
11. Wrap rubber or insulating tape around the valve to prevent it from falling into the combustion chamber. Release the air pressure.
12. Check if the valve surface is damaged. Rotate the valve in the guide bushing to check if it is bent.
13. Move the valve up and down to make sure it does not stick. If the valve sticks, it is either bent or damaged. The cylinder head will need to be removed to repair it.
14. Pump air into the cylinder again until the valve closes. Remove the tape from the valve.
5.15 Install the gasket in place by driving it in using a bushing and a hammer.
15. Lubricate the valve with engine oil and insert a new guide gasket (5.15).
16. Install the valve spring.
17. Install the spring support washer. Compress the spring and carefully insert the holders into the groove. Apply a small amount of grease (5.15) to the inner surface of the holders.
18. Release the spring and make sure the holders are in place.
5.17 Apply a small amount of grease to the inside surface of the holders
19. Disconnect the compressor hose and unscrew the adapter from the spark plug hole. If you used a rope, remove it from the cylinder.
20. Install the rocker arm shafts and rocker arms.
21. Insert the spark plugs and connect the wires to them.
22. Install the valve cover.
23. Start the engine, check for leaks and unusual sounds from under the valve cover.