Im thinking just run the one even then it may be to fast, I know most guys have a 9 hpr kicker that they use for trolling because the bigger motors idle to fast. Most guys i talk to troll 1-2 mph for the walleys. I have a 85 jhonson and the slowest it will go is 2.5 any slower it stalls. You will just have to experiment with it. good luck and be safe