Do not work on electrical equipment that has not been completely disconnected from a source of power. Doing so can result in serious injury or death.
Water conducts electricity, so do not work in an environment with electrical equipment and water unless the power has been completely disconnected. For equipment that has been hard-wired or cannot be unplugged, seek the assistance of a qualified electrician before proceeding.
It may make more sense to replace an older motor or tool with a more energy-efficient model. You may have to pay to replace bearings, or other components, so it the item is badly damaged or of marginal value, it is probably best to move on. On the other hand, a very expensive motor or tool may be worth trying to save.
Electrical motor specialists can often recover a motor by “baking.” This process may be as costly as replacement for small motors, but may be cost effective for larger, more expensive motors. Do not try this yourself as you may melt insulation or other parts that may cause the motor to become unsafe.