My dads used lots of spals on his xr4i, as they kept breaking all the time, unsually between 18-24 months old, even though hardly used, mostly same problem, seizure due to the internal motor magnets falling/coming away from casing inside and jamming, after the 3rd one he went Kenlowe, more money to start with but 4 years on not missed a beat, and has now worked out cheaper than replacing spals over that period.
tabetha