Aviasport is an authorized Rotax Service center. Have you talked with them about what they think the cause of the deviation? One possible cause of the crankshaft deviation could be an Overspeed?
The Rotax 582 has a TBO of 300hrs or 5 years (whichever comes first) If the engine is at 700 hours and has never received an overhaul (crankshaft replacement) it is way past due!
Regardless, the engine needs to be overhauled and a new crankshaft installed as you stated that will happen by Aviasport.
Cheers!