I recently read an article online that every year or so the water impeller for an outboard needs to be changed/switched out due to wear and misshaping over a period of time. I found a YouTube video on how to do just that on a small less than 20hp motor. It seemed like something I can easily do myself. My question is it that easy to do? Or is it something a boat mechanic should take on now during the busy season? My motor is a 15hp '96 model Evinrude. The impeller is around 12bucks. Bolts for lower unit is perhaps 6 bolts. Once removed and put back together is it wise to put a little locktite on the threads to keep them from coming loose? Simple task for a reasonably mechanically incline fella? Or leave it alone and find a shop do switch it out. Reason why I think it needs to be switched out is age of motor and neglect on my dad's part to have the basic sense that it needed to be done a lot more than if it has ever been switched out. And the fact it takes a few more seconds to shoot water out of check jet stream on on side of motor than I am thinking. Thanks.