Reply To: 66 Fastwin not getting full power

[Kevin Johnson]

I rebuilt a lower unit with all the best parts I could gather together from the four that I have.  Resealed everything with new seals.
The clutch dog and all is in great shape.  Not jumping out of gear anymore, but acting like a slipped prop hun again.   I’ve tried four different props, all testing to be either not slipping or frozen hub.  I’m thinking something is actually worn in the power head where the drive shaft engages.  The only thing I know to do is swap out power heads with another 18hp I have(1969).  Mind you, I’m doing this for the knowledge and the learning curve that accompanies it.  All else is well with this motor.  My spare fastwin seems sturdy with 112 psi on both cylinders.