# Should I install a hydraulic jack plate?



## bulldog (Sep 13, 2011)

I have a 6" hydraulic jack plate that I have had sitting around since I began building my boat. Would it benefit me in any way to install it? Any of you jet guys run one? I don't want to go through the trouble of the install if it is not worth it.


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## Scottinva (Sep 14, 2011)

I have a 6" hydraulic jackplate on my Snyder. I had it installed so that if I wanted to use the prop lower unit I could easily drop the motor. I lower mine slightly sometimes if I am going through really rough water so it won't cavitate. One issue is it moves the motor back another 5-6". My boat has a tunnel so the tunnel was just extended all the way back to the intake. If I had to do it over again, I probably wouldln't have spent the money on it because I have never run the prop on it.

Scott


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## Brian J (Sep 14, 2011)

I don't think that I would. It has always been my understanding that the set back on the jack plates allow the opportunity for more air to enter the jet's intake; therefore potentially causing more problems with cavitation. If it ain't broke don't fix it.


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## Ictalurus (Sep 14, 2011)

I thought you were selling your boat?


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## Darkside (Sep 14, 2011)

No one single answer works. It depends on your specific circumstance.

*A.* If your current set up is working fine and running well, don’t go adding a HJP (Hydrualic Jack Plate).
*B.* If like ScottinVA, you have a need to swap out the jet pump with a prop lower unit to fish lakes and rivers (as I did with my 2006) a HJP is the way to go. You can swap lower units out in 45-60 minutes once you’ve done it a few times. 
*C.* If you’re changing to a new engine, adding a tunnel or need a higher transom and the existing bolt patterns don’t match. You can add/fix the existing transom or install a HJP.
*D.* If you Outboard Jet was not installed correctly and sits too high or too low and the bolt patterns don’t allow an easy fix (often 0.75-1.0” centers) a HJP or Transom Jack can fix the problem.

IF you go this route, we’ve added (welded or bolted) plates to the bottom of the boat or the top of the tunnel (for tunneled hulls) back to the leading edge of the intake toe to reduce the amount of air ingested water that X talks about above. 

Another consideration for situation * “D” * is that most every tin boat MFG has different transom rakes/angles. This angle can be critical to jets. Too much or too little rake can cause capitation even when the engine is set at the correct height. I’ve seen this with some boats that don’t have enough rake. In these cases Transom Wedge can fix a world of problems and they are not too difficult to install. 

https://www.thmarine.com/product.cfm?PRID=195


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## fender66 (Sep 14, 2011)

bulldog said:


> I have a 6" hydraulic jack plate that I have had sitting around since I began building my boat. Would it benefit me in any way to install it? Any of you jet guys run one? I don't want to go through the trouble of the install if it is not worth it.



This is a great question that I was going to ask too. I will have my "new to me" engine on Friday and I worked in a deal with the guy to also throw in the jack plate. Since the motor I'm buying has a complete lower unit (less a prop).....now I can have the best of both worlds. My jet pump will fit perfectly if I want to run the river, or I can leave the prop on it if I'm in deep water. I can't wait to get this rigged up and give it a try.


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## Ranchero50 (Sep 14, 2011)

I think if you get a chunk of angle welded to the back and add a splash shield / anticavitation plate ot of UHMW like Scott did that it will work well.


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## S&amp;MFISH (Sep 14, 2011)

fender66 said:


> I will have my "new to me" engine on Friday


 If I may ask, what engine are you getting? Let us know how your boat takes to it.


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## bulldog (Sep 14, 2011)

Ictalurus said:


> I thought you were selling your boat?



I am still up in the air about it. I really want somethig new but I really like my boat so it is one of those things. I like to have a project and my boat is nearing completion. I can do a bunch of crazy stuff to it but it costs $$ that I will never get back out of it. I am going to put it up for sale and just see if I can get a decent price for it. Those inboard jet Trackers are looking nicer and nicer the more of them I find. And they are relatively cheap.


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## Darkside (Sep 14, 2011)

fender66 said:


> This is a great question that I was going to ask too. I will have my "new to me" engine on Friday and I worked in a deal with the guy to also throw in the jack plate. Since the motor I'm buying has a complete lower unit (less a prop).....now I can have the best of both worlds. My jet pump will fit perfectly if I want to run the river, or I can leave the prop on it if I'm in deep water. I can't wait to get this rigged up and give it a try.



Fender. 

Make sure you set the jack up so that you can drop the enigne 6" so the prop will work. You'll also need to make 100% sure you have that piece welded on to fit tightly against the intake. If it moves, (unrenforced UHMW) water is going to push past it. Been there done that. makes a world of difference. 

If ScottinVA has one, Snuder installed the bracket and it is likely reenforced on 3 sides, or the UHMW is bolted to the top of the tunnel and resting on the trim tabs that comes off the tunnel sides.


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