Jack Plate

[Bret Casselman]

I have a 1984 17 ft Boston Whaler Montauk with a 1993 88 hp Evinrude. I have been seing more and more uses of Jack plates on boats of this size and smaller. I know the purpose of these plates are to get engine further off the back of boat which give you the ability to raise the engine higher out of water. <br />The problem im haveing with my boat is that it is very hard to keep trim, it has a tendency to porpuse. I have mounted a fin on cavitation plate which has help tremendously, but will still porpuse , but is easier to trim out.<br />The question i have is it recomended to use a jack plate on this style boat. Is the transume strong enough for the extra forces of having the engine say 6 inches further back. <br />We have mounted a plate on my dads boat, a 19 ft flats boat with a 150 and it helped out greatly. Im see more and more boats even smaller ones then mine using these plates, but none on a whaler. Do you think the expense for this is worth it. <br />Any info would be appreaciated.<br /><br />Bret

 

[JB]

Re: Jack Plate

Hi, Brett.<br /><br />I had a 4" setback plate (no jacking) on my 1981 Montauk. I used it to avoid redrilling the transom and using lag screws to mount the new engine when I repowered.<br /><br />I believe that it improved straightline top speed, but very slightly hindered maneuverability. I also used a hydrofoil (SE Sport 300) which greatly improved low speed planing and hole shot. Smart Tabs would have done even better, but I never got around to installing them.<br /><br />Bottom line? No. I would not put a Jack plate or a setback greater than 4" (only to simplify installation of a modern engine) on a Montauk. I do not believe it would help the very sensitive nature of the BW 17' hull to trim, and it would handle far less well.<br /><br />For advice from Boston Whaler fans, check out www.continuouswave.com<br /><br />Good luck.

 

[umblecumbuz]

Re: Jack Plate

Porpoising?<br /><br />Trim Tabs

 

[Snookster]

Re: Jack Plate

Trim tabs or a Dolphin on the foot of the motor might be a better choice than a jack plate if trim & porpus is the issue. Call Bobs Machine Shop in Central Fla - they'll set you straight.