2001 Ski-Doo Mini Z Factory Shop Manual, Page 76Get this manual
Section 04 ENGINE Subsection 05 (COMPRESSION TEST AND ENGINE DIMENSION MEASUREMENT)
ENGINE DIMENSION MEASUREMENT VALVE SPRING FREE LENGTH
STANDARD 30.5 mm (1.20 in) SERVICE LIMIT 29.5 mm (1.16 in)
If valve seat width is under the standard or over the service limit value, replace cylinder head with new one
VALVE STEM (outside diameter)
STANDARD INTAKE EXHAUST 5.48 mm (0.216 in) 5.44 mm (0.214 in) SERVICE LIMIT 5.318 mm (0.2094 in) 5.275 mm (0.2077 in)
Measure valve springs free length with caliper, as shown in the next photoNOTE: When measuring free length, ensure not to apply pressure onto spring
Measure valve stem with micrometer, as shown in the next photo
A31C1LA
VALVE SPRING FREE LENGTH