Closely observe the gap between the flywheel and the coil/electronic module to see if the flywheel is wobbly.I put the ms170 rotor in the original recoil starter housing and all looked good, but that is now damaged. It started well after the first couple of pulls, turned off the chainsaw and tried starting again, that's when it broke. I'll try post an image shortly. I'm going to look more into Stihltechs question and Zerojunks info as i'm starting to believe its not the starter OEM or AM. Time to take it apart again. Could probably do it with my eyes closed at this point