I don’t know of anyone with the new parts yet, but the HP is up for every motor in Evo form. Biggest difference will be in Micro (lowest HP, biggest % gain). Micro is going from 6.8 nominal HP to 8.0 HP, an 18% increase. Micro is the only engine class that Rotax claims will have a performance gain (which is strange given Hp is up in all the evo motors). Hope that helps.
Mark, that’s the big question. According to Rotax, the upgrade will make them equal. Internally, the piston is slightly lighter, the con rod has a new coating, and the crank bearing is slightly different. A couple of engine builders I’ve spoken too think a good, upgraded Micro will still be good relative to an Evo. I suspect a high $$, part-matched Micro franken-motor that kicks ass now will still kick ass when upgraded. The big question is the coil; you don’t get the new one in the Micro upgrade. The timing hasn’t changed, so it’s not a required upgrade, but Rotax claims the throttle response will be better.
Clark, that is interesting. Do you know if your friends were doing a before upgrade/after upgrade comparison with a specific Micro, or were they comparing 2 completely different motors (a new Evo Micro vs. an older Max). Because slight motor variation is so magnified in Micro, you really need to do a before/after with one motor.