evinrude mounting

[dcfrost]

I am having trouble arriving at mounting height off bottom of the transom of my home built boat....won't plane off...(20" shaft)....cut out measures 21....obviously not shallow enough to keep the prop in the water....air in prop at high speed.....<br /><br />Must the mount be at exactly 20" or should I allow a little more depth...say an extra inch...(19") to keep submerged.... 70 1978 Evinrude.<br /><br />Tomorrow I haul her from the mooring to do the deed of transom recut.....Help!

 

[Dhadley]

Re: evinrude mounting

No need to cut. Most 20" transoms measure 20 3/4" anyway. <br /><br />Is the hull straight? Does it stay straight? If so you may just have a worn out prop. Or a spun hub. Is there anything in front of the lower unit? It should be clear at least 6" on each side. You should have no problems running at 21".<br /><br />Good luck!

 

[dcfrost]

Re: evinrude mounting

thanks for the reply,,, say more about the spun hub.... prop is worn but not much,<br /><br />Boat is solid, no flex. and is straight, heavy ply with glass epox <br /><br />also motor is clear on either side... I was wondering about water flow characteristics of the hull, and thus the need for greater depth