Valves are ground only with fine-grained grinding paste. To ensure the necessary rotational movements, a rubber suction cup is installed on the valve disc. Avoid scratching the seating surfaces during the lapping process by frequently lifting and turning the valve.
Attention: After lapping, carefully remove the grinding paste.
The lapping process is controlled by appearance, as well as by fuel: insert the valve freely, fill the combustion chamber with fuel, fuel must not flow out through the valve guide. Otherwise, continue the lapping process.