How many gallons are the go motors lasting? I always hear about Nova and RB motors lasting 10-12 gallons before a rebuild is necessary. I don't have time to read through 146 pages so I hope I ma not repeating a previously asked question. Right now I am looking at the 5 port motors. RB, Nova and thought if the Go's are lasting just as long and can save a few buck then I would give one a try.