Valve Spring: Testing and Inspection

Checking Valve Springs and Valve Spring Pretension

Specifications:





Checking:








In the event of repairs, check valve spring for corrosion prior to reusing.
In addition, check spring force at specified length by means of a spring test scale. If the value is below lower limit, replace valve springs.
The force of the two valve springs when the engine is installed is 1147 - 1245 N for engine 116.96 and 1000 - 1245 N for engine 117.96. If this force is not achieved in the case of lowered valves (valve seat machining), place a steel washer (1.25 mm thick), Part No. 116 990 26 40, below the Rotocap (valve turning device).
The contact surface at the cylinder head for the Rotocaps has been increased by 1 mm. This ensures that the valve force is main- tamed if the valves or valve seats are reworked in accordance with specifications.