Originally Posted by Capt. Frank (Post 521045)

Gerry,

I'd vote elsewhere given his symptoms. Hub speed this consistent?

The more times it spins free of engine-to-prop the less friction the hub has left for the next time it happens. And progressively slippage gets worse.

And during a hub slippage it emulates cavitation where prop thrust speed would drop off to near 0. He's maintains consistently 3 knots slower?

Could it be as simple as his GPS was knots v mph on the read out? Perhaps.

I think we both agree it's not the powerhead.

Originally Posted by Gerry Zagorski (Post 521061)

Some good observations there Frank although I think I only understood about half of what you said ;)

Definitely not the power head though....