I have a 1989 Barefoot Nautique with a 454 (reverse rotation). The motor will not turn over with the starter. I can turn it by hand so I know the motor is not frozen. Doesn't have a timing chain (has intermeshing gears) so I know the valve timing is on. If i pull the plugs, the starter spind the motor freely. Anyone know what's going on? Can it be a bad starter? Weak battery? Any opinions?