Translations:KAVAN S15-S180A/R FS30-FS180AR - Instruction Manual/62/en

From KAVAN RC Wiki

Adjusting Valve Clearance on Four-Stroke Engines

The valve clearance is preset by the manufacturer and does not require further adjustment by the user. In normal operation, it is advisable to check the valve clearance regularly - for example, if you regularly fly every weekend, you should check the adjustment approximately every 3-4 months. The procedure for adjusting the clearance is given in the appendix.