RE: More lapcat2/7.5 kb probs
Yes, that is very important. It helps to control slop plus works as a bearing surface. If you can't find a K&B washer for that, Prather, Octura and Aeromarine among others use the same basic thing on their driveline so some Hobby Shops carry them.
Man, I hope that your rivers aren't like the ones here in Michigan! I haven't seen them this high since some pix that my Dad had back when he was a kid. I went by my practice pond on the way home from work a little while ago and it has to be easily 3-1/2 higher than usual.