RE: Aquacraft Super-Vee 27 Nitro.
It's not always possible to get extra fuel out by just pulling on the starter. If it seems harder than normal to pull, remove the plug, pinch off the fuel line, hold the boat sideways (header down), and pull the starter a few times. This will allow the fuel to drain into the exhaust. Then hold the boat bow up to allow the extra fuel to drain out of the pipe. Reinstall the plug, unpinch the fuel line, and try starting it again.
Edit: OS #8 is fine for lower nitro fuel (<30% or so).