Greg,
A BCB hydraulic jack plate is a specially built application that was designed in the mid 90’s. It has a custom 6 bolt plate mount which accomodates longer plate frame rails.
Those rails extend the length of the transom and eliminate pivoting of the plate on the transom.
That pivoting condition exists on all other boat applications because of the lever and fulcrum action that a jack plate has and the position of the lower 9″ wide bolt holes. The upper ones are basically 12″ apart. The extra 2 bolts are on the wider pattern as low as we can go inside most flooring applications inside the transom. We also use a 1/2″ aluminum backing plate on all of those 6 bolts.
Most jack plates end just below those bottom two (2) holes and the plate assembly then is alowed to move against the transom when in rough water or hitting and object, mud bar or sand bar. That instantaneous or even a much slower mushy mud bog stopping pressure places a tremendous amount of leverage on a transom and the pivoting then occurs on the plate assembly of shorter plates. Let alone topping waves and more.
Thus the transom is actually forced to bend or bow and the upper pressure on the top mounting of the splash well, or non splash well boats is exerted at a higher level. Hence damage can be increased or exist from that lever action on the transom.
Your FTD and all BCB models have the only all fiberglass, one piece, vacuum molded transoms. Even a 25 HP rated Phelix has an all fiberglass transom.
So it is not the stregth of the transom. It is reducing issues we will face as a manufacturer and the second, third, fourth or fifth owner will as well. Eventually it can create an issue for someone which reduces the integrity in one area or another.
We try to make BCB products withstand years and decades of usage. No doubt we will face challenges with changing products, aging materials, newer materials as things change with EPA regs’. and more. Through all of that we want to lower the consumer issues.
Keeping our bolt patterns in the processes does lower the problems we will face.
Over the years we have seen 8″, 10″ 12″ and even the Mercury Paralift. Virtually every boat with a Mercury Paralift will have some form of an issue somewhere. And those plates going in reverse will have lesser issues to the most common 6″ models.
Simply put it stops the pivot and reduces leverage.
Most all plate manufacturers offer a BCB bolt pattern though it will have to be a custom order with some. As long as you stay within BCB guidelines, you will be fine.
Hope this helps you to understnad what the issue is and the reason for the stipulation.
BCB
The BCB Design adds ano
.
