Here is the deal with coaster brakes. I am not saying they are the best, and I'm also not saying they should be solely relied upon. However, they NEED regular and PROPER service from DAY ONE. This means learning how to disassemble, service and reassemble them YOURSELF. Whether motorized or not, the factory grease won't cut it for very long. I have seen and heard of coaster brakes fail after only a few stops, brand new from the factory. It takes some practice to get it right, but what you need to do is take it apart, clean the old grease out of the bearings the best you can, and re-grease them. I've recently found that the easiest and least messy way to grease bearings is to put some grease on your fingers and smear it around the inside of the bearing cage until you can see it between the ball bearings. You will likely smear it on the outside as well, scrape it up with a finger until you've gotten as much grease in the bearings as you possibly can. And remember that coaster hubs have three bearings, make sure you get them all. Also clean the old grease out of the races. I use Lucas red and tacky grease. If you are keeping the coaster brake intact, also smear some grease on the brake shoes. But the best thing you can do with a coaster brake is convert it to freewheel. Simply remove the brake clutch and shoes and put 3 washers in place of the brake clutch. Then add a rim brake if possible.