Just put a manual jack plate on my old Whaler, what height should I start it at ?

bang4dabuck

Petty Officer 1st Class
Joined
May 24, 2009
Messages
296
It is MANUAL (Rite-Hite 6" setback, 90 HP Evinrude 1968 hull 16'7"). More interested in improving overall performance vs out of the hole shot. What height should the center of prop hub be in relation to keel of boat, at least to start out with ? Continuous Wave board, they must be all out fishing.
 

ddrieck

Senior Chief Petty Officer
Joined
Jul 12, 2007
Messages
667
Re: Just put a manual jack plate on my old Whaler, what height should I start it at ?

Start with your anti-cavitation plate even to 1'' above the very bottom of the keel an go up in small increments from there until you cavitate and then drop back down a bit, you have found the sweet spot
 

bang4dabuck

Petty Officer 1st Class
Joined
May 24, 2009
Messages
296
Re: Just put a manual jack plate on my old Whaler, what height should I start it at ?

Good answer.

Thanks
 

NSBCraig

Lieutenant Commander
Joined
Aug 21, 2007
Messages
1,907
Re: Just put a manual jack plate on my old Whaler, what height should I start it at ?

^^^
 

alwims

Petty Officer 3rd Class
Joined
Jun 8, 2006
Messages
89
Re: Just put a manual jack plate on my old Whaler, what height should I start it at ?

Start with your anti-cavitation plate even to 1'' above the very bottom of the keel an go up in small increments from there until you cavitate and then drop back down a bit, you have found the sweet spot

Not meaning to hijack, but can you explan what you mean by, " until you cavitate"? Sorry for the dumb question.
 

5150abf

Vice Admiral
Joined
Aug 12, 2007
Messages
5,808
Re: Just put a manual jack plate on my old Whaler, what height should I start it at ?

Cavitation happens when the prop is too close to the surface and sucks air, the engine picks up rpm and you lose thrust till you lower the engine and it is in clean water again.

It is comparable to hydroplaning a car, the tires lose traction and spin without providing forward drive.
 
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