I have a Bertram powered by twin Ford V8s, and the starboard 351W will only rev to 2800rpm under load (it revs freely to 4800rpm in neutral), after this any more throttle causes a flat spot and drop in the vacuum gauge reading (15psi to 3psi or sometimes zero) with no more power. there is also...
I have recently bought a 115HP Johnson outboard mid 70's and originally I guess it was meant to run on leaded fuel with a 2-stroke oil. Is it ok to run this on unleaded fuel with a 2-stroke oil mixture or should I be adding a fuel additive too??
