Valves may be lapped only using fine-grained grinding paste. To perform the necessary rotational movements, a tool with a rubber suction cup is installed on the valve head. The formation of scratches on the seat chamfers during lapping is eliminated by frequently lifting and uniformly turning the valve.
Note: After lapping, the grinding paste must be carefully removed.
The appearance of the working surface during the grinding process can be controlled using Preupischblau or Bleiweiβ, as well as using fuel. Freely insert the valve into the guide, fill the combustion chamber with fuel, the fuel should not leak to the valve guide. Otherwise, repeat the grinding process.
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