THE BIG DEBATE is the 40:1 PREMIX RATIO. I been rebuilding the Rotax 2 stroke crankshafts since January 2011. Since then, I have learned a lot. Most other manufactures use 2 piling slots at the lower eye in the connecting rod to supply more oil to that prone to fail bearing. WSM, a large improvement company, builds replacement rods for the 582 engines with the required 2 oil slots. Now PLEASE understand this: every two out of three 582 engines that fail, does so in the lower rod bearing, which burns up causing the failure. Since I started rebuilding these crankshafts I have NEVER had one single 582 lower rod bearing fail. WHY? 70% of the cure is 40:1 gas oil ratio. The other 30% is due to the double oil slot.
this is from rotax rick , what don mentioned earlier.