Translations:KAVAN S15-S180A/R FS30-FS180AR - Instruction Manual/77/en

From KAVAN RC Wiki

3. The correct clearances are between 0.04 mm and 0.10 mm between the rocker arm and the valve. A 0.04 mm feeler gauge (the thinner one) can be inserted, a thicker one (0.10 mm) cannot.