Pulled the motor today. wow compared to a cheapie chinee rear direct drive bike, removing & accessing the motor innards on these is a breeze!
Found 2 or 3 of the motor mount bolts loose - 1 or 2 were only at 50 inch lbs (5.6 Nm), 1 was finger loose, and the other 3 were around 170 inch lbs (19.2 Nm) - factory spec is 10-12.5Nm....maybe they got tight due to the little bit of corrrosion of the aluminum frame I found?
I also saw some evidence of rubbing on some of the mating surfaces at the mounting bolt locations. I haven't re-assembled yet but pretty sure that is what was causing the creak noise (it was real bad). Pulled the motor casing and since I didnt have the right type of grease i just found blobs of clean grease that were displaced and not doing anything and re-applied to the gears, it'll do for the rest of the season before i do a tear-down over the winter maybe. with ~2000 kms on it, thinking it might be due.
Also, noticed on the right side motor mounts, the motor has threaded inserts going through the mounting holes - maybe steel for higher torque on the bolts than aluminum could take? but these inserts present another potential source of the creaking. I checked all 3 inserts by grabbing their flanges with some pliers - they are tight, but who knows with the amount of torque on the cranks there might be movement there...if the noise is still present i'll consider pulling the inserts to check for evidence of rubbing, but they'll be damn hard to remove i bet if they're press fit. I'd reassemble them with some loctite bearing mount maybe....
Should I use something stronger than blue loctite to secure the motor mounting bolts this time?