RE: Another new boat LOL!!!
I had pretty good luck the last time I used my AM system on maggy before I got my 2nd FASST RX. All I did was ground my flex shaft and most of my interference problems went away. Not a fix for every interference problem, but it's simple enough to do. Save up some money and get yourself a 2.4ghz FASST radio, and don't look back.
Yeah Leo that radio box needs to be redone, god knows how the guy before you was taping the lid down and keeping the water out. I'd definitely get a 1/4 scale servo before running her. They can be found at servocity for under $35-$40. If you don't already have one I'd pick up a 5 cell Nihm RX battery, those AA's are nothing but trouble. Water pump needs to be moved, looks like your pulse line is pushing 9" long. It needs to be no longer than 4" and the shorter the better. I'd also use a different hose for the pulse line, that looks like vinyl or silicone tubing. I know Leo was using something similar to vinyl tubing but stiffer in one of his boats, forgot what it was though. Can't go wrong with a short piece of 5/32" tygon or even 5/32" vacuum line.