Hi guys, for your records below is the official answer I got from the factory concerning conrod life for the Sirio S12. Also I did measurement to crank pin on a new stock engine and found that it has 4.428mm.
Hope it helps everybody
AFM

"The right play between crank pin and conrod bushing is 0,04 - 0,05 mm. I don't know if you're able to check it, but I suggest you change the conrod every 2-3 hours running.
The life of the conrod depends mainly on the fuel you use, as the lubrification and the right carburation keeps your engine running well for long time."

Regards,

ANDREA ROSSI
Lavorazioni Meccaniche srl
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