The motor is brushless and should last the life of the car, whats likely weakening are your batteries. What you describe sounds like recalibrations. If the battery SOC suddenly drops to nothing and force charges back up. This behavior seems to be in some 2000 Insight's, especially at higher mileage like yours. Unfortunately your completely outside of warranty so your best bet is probably to just drive it till it dies completely. A replacment will run you about 3 grand from Honda unfortunately. Eventually you will probably get a IMA light once the pack gets weak enough that the car decides it's no longer usable. This of course could be a long time though.