Re: Thrust question
Certainly -- but probably not so much that you would notice it. Bearings can become worn or tight and brushes can lose a little efficiency. Fish line wrapped around the shaft can cut the seal allowing water inside the housing or it may cause significant drag. I've seen many motors with fish line wrapped very tightly. A dinged prop can also affect performance. The battery losing capacity would make you think the motor is weakening but its really the battery.
