First Run!! I bought this off eBay and upgraded the electronics to modern ESC. Dates from the 1980s. Running the 550 size motor on a heavy 8.4V NiCd pack I made from a drill battery. Could do better with a lighter pack. Also have some things to try for motor set-up. This was the first time I'd ever run an R/C boat of any sort - still learning my right from my left!