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SthurmanFW

HPX-T ideal motor height

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I just "switched out" my '04 HPX-V 18 for a '05 HPX-T as the big girl was too big for my fishing needs on the TX coast. 

I know there is a lot of conversation out there about Jackplates (I've searched many forums on that subject) on the T and it seems that the consensus is that you really don't "need' it but many run them and love them.

Mine does not have a JP and I'm not planning to add one but I do have a question about motor mounting height and if the T owners on this forum have a recommendation.

I've noticed in some pictures of HPX-T's either in ads or on the forum that the motors are generally hung a few holes up on the motor mount, not all the way down in the last whole which is where mine is currently.

Does anyone have an opinion on optimum height for the TX coast with the tunnel hull. I haven't run it myself down there yet and wanted to get it set up properly before I head down there the first time if possible.

Interested to see what everyone has to say.

Thanks

ST

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I have a 2011 HPXT and do run a jack plate. I am very happy with it and would install another if I was starting over. I tend to run the motor pretty high (4 - 5 on the JP) most of the time but there are times I run it deeper as well as times when I run it at the top.

That said, I have been on a T without a JP and the owner (Rockport guide Chuck Scates) was very adamant that he did not need one. He did have the motor mounted as high as possible and just used a lot of trim, along with tilting the boat over as much as possible, to get shallow water hole shots.

While I do think you want the motor as high as possible to make full use of the tunnel and shallow water performance, I also think the prop dictates how high the motor needs to be to stay happy. I am currently running a 3 blade PT SWW series prop and it likes to run high in the tunnel. On my last  boat, a PF 17T, I had a Performance wheel and it preferred to run deeper in the tunnel.

Good luck!

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Good point - I put a Shaw wing on my PF 17t. Definitely helped with hole shot and keeping adequate water pressure. Didn't see any negative effects on top end as these are already slow boats without the plate. I haven't seen a plate on a HPXT but doesn't mean it won't work.

I am a big fan of Kevin Shaw and his products. His factory is in Corpus and you can work direct with him on plates and push poles. Give him a call as he is very familiar with the HPXT and how to set one up.

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I've owned alot of tunnel hulls, all used in the LLM. All have had jackplates and a fiberglass compression plate except for my HPXT. 2 Dargels, 2 Shallowsports, 17t and a Curlew. All ran 4 blade props. The Hpx was noticeably slower up on plane than the 17t, yam 70 2s vs Yam 60 2s. The 17t did not have tabs, the hpx did. The 17t had a manual jackplate the hpx did not. Even with a manual jackplate, the motor mounting is several inches higher on the 17t. When I bought the 17t, the dealer had the motor mounted 2 holes from the highest, water would hit the antventilation plate and spray over the transom. Added a 4 inch setback plate and top holes on motor are several inches above the top of the transom. As to motor longevity effects, that boat was bought in May 2000 with a 60 Yam 2s and I still own and runs like new despite spending most of its life in a hyper saline lagoon. The fiberglass plates are made by Stiffy, Dargel and Shallowsport as well as others so shop around, it's a pretty simple device and I think optimizes holeshots in shallow water.

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On 1/11/2018 at 2:09 PM, RobVan said:

I have a 2011 HPXT and do run a jack plate. I am very happy with it and would install another if I was starting over. I tend to run the motor pretty high (4 - 5 on the JP) most of the time but there are times I run it deeper as well as times when I run it at the top.

That said, I have been on a T without a JP and the owner (Rockport guide Chuck Scates) was very adamant that he did not need one. He did have the motor mounted as high as possible and just used a lot of trim, along with tilting the boat over as much as possible, to get shallow water hole shots.

While I do think you want the motor as high as possible to make full use of the tunnel and shallow water performance, I also think the prop dictates how high the motor needs to be to stay happy. I am currently running a 3 blade PT SWW series prop and it likes to run high in the tunnel. On my last  boat, a PF 17T, I had a Performance wheel and it preferred to run deeper in the tunnel.

Good luck!

Do you low water pick up on your motor?

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I don’t have low water pickup, how does that get installed/used?

I did speak with Kevin Shaw and he said run it on the top hole, all the way up. I run a 4 blade PT prop

Does anyone know if it’s possibl to get the motor raised up without taking off the platform? It’s the original platform not the shorter one people have changed to that sits in front of the motor.

Thanks all!

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Low water pickup, can be factory installed but you can also use different companies, I know Bob's Machine Shop does them.  Basically it adds holes to the cone of your lower unit or a lower vent hole so that you can run with your motor higher and still get good water pressure.

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On 4/24/2018 at 8:13 AM, SthurmanFW said:

I don’t have low water pickup, how does that get installed/used?

I did speak with Kevin Shaw and he said run it on the top hole, all the way up. I run a 4 blade PT prop

Does anyone know if it’s possibl to get the motor raised up without taking off the platform? It’s the original platform not the shorter one people have changed to that sits in front of the motor.

Thanks all!

I think if you raised the motor more than a few inches you would not be able to trim/tilt the motor out fully. You might also have trouble taking the cowling off. You could measure and test those issues easily enough. 

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Just to bring this one back to life a little bit, I made three changes to my HPX-T a few weeks ago.  Although I'm still testing them out, I'm really happy with the results so far. The three changes were:

1.  Raising the motor to the highest mounting position (it came from the factory in the lowest position),

2.  Installing a New Water compression plate, and

3.  Putting on a Jack Foreman prop (heavy cup, heavy blade 3 blade).

Since I made all 3 changes at once, it's a little hard to say which ones get the proper credit, but I'm just glad it works well.  The point in doing this was really to improve the shallow water jump up ability as the boat already ran as skinny as any sane person could want. Often it's easy enough to pole off the end of the flat or find a ditch or big pothole to jump up in, but we do have miles of very shallow flats in Texas where that can be a very difficult.

Raising the motor was a no-brainer, and I don't know why I had never considered that.  That gives me about 3 more inches of elevation when I need it with absolutely no downside that I can see.  That was a pretty simple DIY project.  I just blocked under the skeg with a 5-gallon bucket, then took out the top mounting bolts and loosened the bottom ones.  Then I used the jack stand to the trailer to raise the bow, which dropped the transom and pushed the motor up to the new mounting position.  Thank you for that clever solution, internet!  If you do this, be sure to pull some extra slack in the lines going up to the motor so that it can still turn fully in each direction.

I bought and installed a compression plate from New Water Boatworks in San Antonio on the advice of prop guru Jack Foreman.  It is very pricey at $500 compared to about $300, I think, for a Shaw Wing, but it also comes in a nice gelcoat (black or white) finish and you can order it precut for the F70 (or whatever) motor which saves a lot of work.  I hoped the compression plate would keep better water pressure at elevation and perhaps provide a little aft-end support for a flatter hole shot.

Finally I added one of Jack's props that he said he had perfectly dialed in for the HPX-T/F70 combo.  I've run a PT SWW3R in 14 pitch for years.  It is a really good prop for running and maintains great grip at full elevation, but either because of the prop, or quite possibly operator error, I felt the prop would not grip as well on hole shot and and the stern would dig down.

So what are the results so far?  I had one initial concern when I found that the water pressure would drop off quickly above 3" on the jackplate.  But at the new mounting position, that's really the equivalent of 6", or full elevation, on my previous set up. I very rarely ran that high anyway, so once on plane I feel I have plenty of elevation anyway at just 3" on the jack plate.  But now I can still raise it to 6" for the hole shot when I need to.  It takes me only a few seconds to get on plane, and then I can drop the plate back down to 3" for running out and I"m getting 20+ psi on the gauge.  That works really well.

I've only done a handful of shallow water hole shots so far, and none super-skinny, but it definitely feels much better. The prop really grabs right away at full 6" elevation and pushes the boat forward into a full left turn, where before i would have trouble hooking up and the boat tended to skid slowly rather than propel forward to get some planing speed.  It also takes off without the big bow lift/stern dig I had before, which really helps.  How much of this is credit to the prop and how much to the compression plate, I don't know.  I could swap the prop back out just for some testing, but this one works and I'm too lazy to go to the extra work.

The only other thing I have considered is a low water pickup like a Bob's nose cone.  It wouldn't be necessary for shallow water jump ups, and I think I can already run shallow enough on plane with the factory intakes.  But i think it would help to keep from getting the intakes clogged with floating grass which can definitely be a problem from the middle Texas coast and farther south.  But enough is enough for now and I'll see how she does this summer before resorting to any more invasive surgery like that.

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Great post Bruce

Excellent information

I have a few questions for you if you don't mind

What year is your T and where did you get the smaller poling platform?

Did you put those drain holes on the sponsons? I've heard the T can take on water in that area through the rub rail or design flaw. I've seen video of someone drilling into the hull in tat area and copious amounts of water coming out. How would one know if this is occurring? I'm not super keen on drilling holes in the boat below the water line if not necessary.

I need to raise my F60 but do not have a jack plate or a water pressure gauge and have considered a compression plate but the boat really performed well the last time I had it in Port O'connor so not sure I need to change much but thought the motor height would be a small but noticeable change in hole shot performance. I think it will fit still under the standard platform since I don't run a jackplate. Some Day I may go with a smaller platform like just about all the serious HPX-T owners seem to have done. I currently don't use the boat enough to spend that kind of cash. So you really did that motor adjustment yourself? Can you please point em in the direction of the video that showed you how? I'm definitely a little nervous about "trying that at home" as they say.

Who did your power pole install? Did you do that yourself or did you use a marina/service dept? I was planning on trying that on my own as well but very nervous about tapping the plate that is supposedly part of the initial build. Any thought you have on that would be appreciated as well.

If I do raise the motor, how do I know if I "need" a water pressure gauge or not and how easy are those to install?

Sorry for so many questions you just seemed to be very well versed in all this HPX T stuff.

Once again, phenomenal post, thanks for resurrecting.

ST

 

 

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Hi ST, and I'll try to get to all of your questions.  First, as some background, my first HPXT was a 2002 so it was set up much like yours, but with the 2-stroke Yamaha.  My current one is a 2011, made in 2010, and it was the first year they came out with the revised deck layout, the smaller forward platform, a factory jack-plate option, etc.  That's really why Brad and Skip were able to strong-arm me into a new boat.  Just kidding on that, of course!

But even with my '02, I ditched the factory "tall" platform and had one made by a local fabricator to sit in front of the motor.  Even though I didn't have a jackplate on that boat, I really liked the more forward platform as it was a bit lower (about the height of the motor, and having the weight a bit more forward helped with the poling draft.  I would highly recommend that if you plan to keep yours for a while.

I didn't have a water pressure gauge on that older boat, but since I couldn't jack it up, I don't think I really missed it much at the time and didn't know any better.  But now that I'm used to having one, I know it would still be helpful for other reasons like to know before your heat alarm goes off that your intakes get clogged up with grass or other debris, or to monitor the health of your impeller. I suspect that's a pretty simple and inexpensive addition (unlike adding a new platform or jackplate).

On your boat, I doubt that raising it a few inches would present any real risk of overheating.  When I didn't have a jackplate, I always ran my boat trimmed well out anyway and don't think I had any problems.  I think being mounted in the highest position would be the place to start on an HPXT.  If your overheat alarm goes off even when you're fully trimmed down, it's an easy fix to just drop the motor another notch.

Regarding the DIY of moving your motor, I don't recall finding a video, but I just heard a description of exactly what I did, and it worked beautifully, even single-handed.  I took a five gallon bucket and put a few boards across the top of it.  Then put that under the skeg.  I took out the top mounting bolts and loosened the lower two which are in slots, not holes, like the top bolts.  So the motor is never completely disconnected from the transom. Then I went up to the jack stand (be sure you block your wheels!) and i raised the front of the trailer about a half-inch at a time until I could align the top bolt holes. If you had a spotter at the back of the boat, it would be even easier.  Really the whole thing was much easier than expected.

I did add the drain plugs myself, and absolutely recommend doing that.  I had to bore out the factory hole just a bit as I recall to get them to fit, but it was well worth it. I love not having to hunt around for plugs or worry about dropping them into the drink.

Regarding leakage into the transom, I too have read about others with this issue, but I have never done anything to check on either boat.  My '02 was dry as a bone in the bilge.  i rarely had any water in it at all.  I could have had water in the transom, but never felt like I had an issue and didn't check.  Same with my current boat.

The factory installed the PowerPole for me, but I suspect any reasonably competent boat rigger could manage that for you.  I love having the PowerPole for many reasons, although that too is a pretty pricey addition.

I might have missed one or two of your questions as I didn't take much of an order going through them.  Please try again with any others.

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