Serious Jackplate Questions

[1FASTLASER]

I do not know if anyone has ever tried this before but I have an idea in my head and want to get y'all's opinion.
With the wide array of professionals here someone please tell me.. The old style in the boat trim pump that Mercury used to use on there Inlines and such.....would it handle the duties of being used for a hydraulic jackplate? If so I will be building a hydraulic jackplate with VERY minimal setback?
Second question pertains to jackplates as well. I think I have got all the quirks worked out on a jackplate that not only moves vertically but also while jacking up will move horizontally (away from the transom). The plate will certainly handle the workloads and the stress of a outboard. Would there be any other issues (setup issues) that I should concentrate on other than strength,weight and reliabity? I have mocked one up out of wood and it works and I have the material available to pursue this in metal if enough of you think this would be beneficial. I want to cover all bases before pursuing and as y'all know several minds are usually better than one

[TEXAS20225]

sounds like reinventing the para-lift from years back i have a trim pump that i was using on a jack plate 5/6 years ago its works great i also have a para lift that need ram resealed to be back up to snuff

[roadkill636]

I got one on my Jon boat. 6" setback when down and lifts 6" and gos to 9" setback.

[1FASTLASER]

In a sense yes Tex but totally diffent design. It will be stronger,more reliable,less moving parts or actually I should say to be politically correct less pivot points which increases strength and longevity
Roadkill lemme c a pic if you will and how does she perform??

[tlwjkw]

may not really apply but have a very inventive x-machinist down here with lotsa time, material, machine shop available. didn't think it would be any count but works excellant and has held up ta some purdy good testin' for several years. fabed an up down, in out trim single bracket (for both motors) with twins ona 21' liberator. used tha 2 small, ole style cyl. for in n out and later single cyl. for up n down. uses 2 pumps. have ta admit it all looks really nice too. used all good stuff for it. tha larger stuff has very concentric holes ta take some of weight off. its purdy impressive, 'specially from a T-rex type.........kinda reminds me of that two motored champ bass boat but tided up quite a bit.....jus sayin'. wanna try sumin' different, get after it!........

[frederick55]

I use a Merc hi-perf trim pump on a CMC Allison jackplate and it works great. Cost 75$ for fittings to make the compatibility change. Faster than the original pump.

[roadkill636]

I dont use the jackplate for bow lift what so ever. Rember its on a 24' hunk of metel thats a full 8' wide. I just use it for shallow water running when on the river and getting up to sand bars.
pics from an old post a few years ago on propshaft height

[dompie99]

I also use at the present time, an external trim pump for my jack plate and it works great.

[LFP]

I'm looking for the little rubber button that fits in the relief valve plunger on a Land & Sea plate with one piece Prestolite pump/cyl. Daimeter is .172" and 1/16th " thick. Working side has a sealing perimeter ridge (mine has failed causing leak down). I'm at [email protected] in Seattle. Again, I apologize for a non-responsive posting but I wanted to get the attention of the knowledgeable.

[1FASTLASER]

Thanks folks for all the replies. I think i got everything covered now so as soon as work slows up abit Im fixin ta go ahead and build this plate and see how well it works.

[LFP]

I guess I have something relevant for you. My model jack plate fails to hold position and leaks down. Typically a tilt motor is relieved of pressure when you back it down on to the mechanical stop for trailering. The jack plate is left at at preferred position solely by hydraulic pressure. this may explain why I found a rubber valve seat in the bypass valve. All the marine shops said this was unlike the tilt motor's ball check valve. I think the ball check valve may eventually leak down scraping your skeg on whatever. They designed my jack plate with a rubber seat for a positive seal to hold position for months.
As long as I am rambling, there are forces beyond your intuition and expectations between a big outboard and a transom that engineers design for. I put on a wetsuit and skiied in the wake of my big outboard in Desolation Sound. I watched the boat ride over a submerged log and the outdrive hit it. the outdrive came up while the powerhead went forward while I skiied around the deadhead. No damage! The rig had been engineered to handle these unforseen and exceptional forces.

[rgsauger]

Try mcmastercarr.com and search for rubber plugs on there