Funny how it works. The 18 ft alumawelds seem to do best with a 90 or maybe a 115 tops. I have seen em with 125's and even 150's and they all float ass heavy and won't track right like that. But you jump to a 20 fter and they float ok with a 200. So a 90 on a 18ft does sound underpowered and it is with the 4th guy in, anything bigger would start to work against you. In the market for a 21' with a 200.