Mxus XF08 4.4:1 hub motor stripping

[Trevonsphere]

one of my bike-builds came back for some unrelated work, and I noticed the hub motor, the 4.4:1 mxus xf08 was a lot coggier-sounding than the bike I ride most of the time, also with an xf08. So I took it for a fast 30 minute run on tarmac, and what I had been half-expecting happened: gears-stripped noise and no traction from motor after 10 miles. Strangely enough, switching the battery off then on again gave me another few miles assistance, as long as the throttle was used lightly. Did this several times and it got me back.

I've just got around to opening the motor, expecting to find it full of chewed plastic. But to my surprise, the sun and planet gears look a fairly chunky build, are all fine, not the least damage. Wondering now if it'll be the clutch, or a loose rotor magnet or such like, before I strip out the rotor to find out... It's been ridden for several years by a lad who likes his stunt riding! It's at 48V with a throttle, normally ridden in the UK, so unlikely to have got seriously hot. Not hot [17C ambient] the day I took it out (in Portugal). Note the motor wiring looks a little loose and frayed to me. Any xf08 stories of any relevance? And tips for parting the rotor and stator if needed?

I also noticed a few times before taking it on this test run that it's made a jumpy or rattly start, like a dodgy hall sensor or cable, but that seemed to clear up after the weather got less damp. Now wondering if that might also be caused by a loose magnet.... or even have caused it!?

 

[Trevonsphere]

Today I pushed-off the cover complete with bearing from the chain-side of the motor, and the epicyclic gears mounted on the freewheel on the other side. This enabled a clear view of the windings. They've must have gone briefly above 220-ish C to melt the nylon of the cable ties and lacing cord. So the epoxy holding the magnets in the rotor may also have let go enough to allow one or more to leap out of their gap and contact the rotor with a lot of torque on them. Guessing that may be the "stripped gears" sound I was hearing, which sometimes was not actually a sound of significant duration, but just a "bump" followed by loss of motor drive.

So now I'm going to wait a bit for replies again, before pushing the rotor off the stator, as I want to minimise the risk of getting any metal particles stuck to the "unkeepered" magnets, or damaging anything in the pulling process. Hoping for input from someone who knows this motor before proceeding. Slightly baffled by the circlip between the freewheel clutch and the rotor: it has no pliers holes, but managed to ping it off from a slot in the shaft. Wondering how much of the resistance to manual attempts to remove the rotor is magnetic, and how much is stiction on the bearings.

Anyone know or have a photo of what's inside the xf08 riveted sealed clutch assembly, or similar, out of interest?