Hi Ron, you are not missing anything - ROTAX is still in the process of developing a web portal for self-service engine serial lookup. We will have it online here as soon as it is ready - but we do not have a firm ETA for that yet. In the meantime, I can manually look up this info for you through the factory database....
6783139 is a ROTAX 912 ULS (912 ULS2) produced 01-Mar-2014
original factory configuration:
with fuel lines
UL2 I=2,43 with clutch
without vacuum pump
with green valve covers
without mech. tachom. pick up
without external generator
without air guide baffle
with std. temperatur sensors
with screw connection UNF
with expansion tank
without air box
without engine truss
starter large