2. If more thorough work is required on the head, it should be disassembled so that the valves can be lapped, the parts cleaned and blown out with compressed air. It is also necessary to clean the collectors (in particular the exhaust manifold, where carbon deposits are most likely to accumulate).
3. Before lapping the valve, completely clean its head and stem from carbon deposits and deposits. In the case of an inlet valve, you can simply remove the carbon deposits with a dull knife and then clean the valve with a wire brush. Carbon deposits from exhaust valves are much more difficult to remove. One method to quickly clean the valve is to clamp it in the chuck of an electric drill with foil to prevent damage to the stem. After that, you can turn on the drill and thoroughly clean the valve with a scraper or wire brush.
4. An important part of the head cleaning operation is the removal of carbon deposits from the piston crowns. To do this, turn the crankshaft so that 2 pistons are at the top of their stroke, and press a little grease into the gap between these pistons and the cylinder walls. This will prevent soot from getting behind the pistons and into the piston grooves. Cover the remaining 2 cylinders with newspaper and securely fasten it so that the dirt being removed does not get into the lubrication and water jacket channels.
5. Using a blunt scraper, remove carbon deposits from the bottom of the pistons, being careful not to scratch the soft alloy. Thoroughly clean the combustion chambers in the piston crowns.
6. Remove the newspaper from the other two cylinders and turn the crankshaft half a turn so that the other two pistons are up. Repeat the cleaning procedure on these pistons. Wipe off traces of grease from the top of the cylinders.
7. Upon completion, thoroughly clean the surface of the cylinder block.