Disassembly
If only one part needs to be replaced, the cylinder head may not be completely disassembled and only what is needed for replacement can be removed.
Place the cylinder head on a stand, disconnect the hose from the warm air intake, unscrew the nuts and remove the carburetor with gasket, and then the intake pipe and exhaust manifold (at the same time the warm air intake is removed).
Remove the outlet pipe of the cooling jacket and the fluid outlet pipe to the heater. Remove spark plugs and coolant temperature sensor.
Turn away nuts of fastening and remove the case of bearings in gathering with a camshaft. Loosen the nuts securing the thrust flange to the bearing housing. Remove the flange and remove the camshaft from the bearing housing.
Remove levers 11 (pic. 2-43) valves, freeing them from the springs 12. Remove the lever springs.
Pic. 2-43. Valve mechanism details:
1 - valve; 2- retaining ring; 3 - guide sleeve; 4 - oil deflector cap; 5 - support washer of the outer spring; 6 - lock washer of the internal spring; 7 - internal spring; 8 - outer spring; 9 - a plate of springs; 10 - crackers; 11 - valve drive lever; 12 - lever spring; 13 - adjusting bolt; 14 - adjusting bolt locknut; 15 - adjusting bolt bushing; 16 - locking plate of the lever spring.
Loosen the locknuts 14, unscrew the adjusting bolts 13 and the bushings 15 of the adjusting bolts.
Install tool A.60311/R as shown in fig. 2-44, compress the valve springs and loosen the cotters. Instead of the portable tool A.60311/R, the fixed tool 02.7823.9505 can also be used.
Remove valve springs with plates and support washers. Turn the cylinder head and remove the valves from the underside. Remove the oil seals from the guide bushings.
Assembly
Assemble the cylinder head in the reverse order of disassembly. Lubricate the valve stems and oil seals with engine oil before assembly.
Before installing the camshaft bearing housing, check that the housing locating sleeves are in place (rice. 2-20). Tighten the bearing housing nuts in the order shown on rice. 2-22. At the same time, pay attention to the fact that the adjusting sleeves fit into the sockets of the bearing housing without distortion.
Adjust the valve clearances after installing the cylinder head on the engine.