Setback question

[abianca99]

This does not apply to a Stroker, but it seems like you guys have a lot of experience adding setbacks to your boats. This applies to a Triton Tr21/225 ProXS. Currently using a 6" Detwiler hydraulic jack plate. I am wanting to add some more setback to the engine. I was looking at the 4" setback bracket that Bob's offers. Giving me 10" total. I was planning on mounting it between the transom and the setback. Anything I should be aware of before doing this? Will this setback bracket work for my application. I want to make sure that it will be strong enough and hold up to rough conditions. Will his jack plate bolt kit work good too. Should I be looking at anther type of setback? Any input is appreciated. Thanks. Below is a link of the setback brackets I am looking at.

http://www.bobsmachine.com/Pro...s.cfm

[NixaMan]

Detwiler has there own 4" plates through Pit Stop Marine. The Stroker Guys mount the Jackplate against the transom and the plate between the jackplate and motor. Has worked great at speeds over 100 mph.

[abianca99]

I was planning on mounting the fixed setback on the transom, and then mounting the hydro jack plate to that. The only reason was to make it easier to access the nuts to torque them properly. It is a little hard to access them with a torque wrench when the hydro jack plate is against the transom. The pistons on the jack plate are right in the way when using the 4 1/2" bolts that are used to go through the transom. Is there a reason why they are mounting the jack plate to the transom and then the fixed setback to the jack plate? Is it a performance or safety factor? Does it matter? Thanks in advance.

[John Jackson]

Personally, I like the extra weight being against the transom.
However you decide and whatever brand, make sure the largest footprint goes against the transom.

Detwyler is the only aluminum jackplate that I have not seen or heard of breaking. It's thicker & stronger than the others. And with 500+ lb motors, strength is important.

[abianca99]

That makes complete sense. And I totally agree. By "largest footprint" I assume you mean...the heaviest setback and largest set back goes against the transom??? Or the unit with the largest surface area against the transom goes against the transom???

Since you guys have a lot of experience with the detwiler hydro jack plates, how do you deal with the issue of the pistons being in the way of the bolts? Maybe on the larger jack plates it doesn't matter, but on the 6" it is right in the way. It doesn't allow me to put a torque wrench on it. An tips on that are appreciated. Thanks again.

[Stroker300x]

largest foot print would be the biggest push area against the transome
with the detwiler's I always run it against the transom and then add the setback

However Hydrodynamics recomend putting there plate first then the hydrolic plate.

[Strokerdean]

I run the hydrodynamics plate against the transum like Kurt said and the detwiller against the motor. I have also gon to 5/8" grade 8 bolts and nuts with 1/2" alum plate against the inside of the transum to back up the bolts, again recomended by Kurt. This set up works good on my rig.

[abianca99]

Thanks guys. I new you guys would out me on the right track. That's why I asked on this board. I am going to mount the Detwiler to the transom, and then the additional fixed setback to the jack plate, and then the engine to the fixed setback. Sound like the best way for my application? I am curious as to why hydrodynamics recommends mounting there static plates to the transom???

In regards to hardware...I have only ever had 1/2" mounting hardware. That is what has always been on my boat. And it was rigged with SS. If I am not mistaken, grade 8 is a stronger bolt than the typical SS that is used on many mounting applications. My only concern would be rust and corrosion using the grade 8 hardware. Is this an issue using grade 8? How do you guys keep them from rusting and/or corroding? Also, does your standard size mounting holes work with the larger hardware? Or do you have to drill them out larger to fit the 5/8" size. On my boat, I do have a plate that goes across the the splash well that backs up the top 2 transom mounting bolts. Is that what you are talking about, or do you have something else for the bottom 2 transom mounting bolts? Thanks again.

[Strokerdean]

On my rig I have 1/2" thick alum plates on the top and bottom bolts. The Stroker doesn't have the splash well so the plates are under the deck. As far as the grade 8 bolts, they do rust. I had to drill the plate and transum for the 5/8" but I think 9/16" will fit with out drilling, you would have to get a bole or measure the holes. I went to the larger bolts for a little added insurance because of the large set back and speeds I run at although not as fast as the guys that don't run in the clouds. Mr rig came set up with the detwiller against the transum and 4" detwiller spacers that the motor mounted to when I bought it.

[John Jackson]

Stainless is quite soft compared to grade 8, but adequate. I have grade 8, and I double nut the top bolts. The top bolts receive the major abount of extentional pressure. The bottom bolts just shear and compression forces.

[abianca99]

So I understand why you guys use the grade 8 bolts. They are stronger. But they do rust. Do you just deal with the rust and leave them like that? Replace them every so often? It sees like there would be some type of maintenance to deal with the rust.

[Largemouthlou]

Have had mine since May 06 with the grade 8 bolts with no maintenance at all except for re-tighten and they have slight rust on them..

[abianca99]

That's not bad at all. I would have thought they would rust within the first year. I am curious as to why all bass boats rigged with grade 8 isn't the norm? Seems like a better option. Do you guys put anything on the threads of the bolts? Anti seize?

On the bottom transom bolts...I have a brace that goes between them, not allowing for a one piece solid plate like the top 2 bolts have. Do you know of something that will work good for my application? It DOES currently have, what looks like, 3/16" thick over sized washers. They look fairly strong. Not anywhere near like the top plate though. I don't have expect specs on them though. Do you think, for my application, I would be fine using them? My boat sees mid 70's top, but does see some fairly rough water at times.

Detwiler 6" hydro jack plate...currently the 4 1/2" ss bolts come through the transom, with a washer and nylon ss nut on the jack plate side. This is the direction of the bolts that my Detwiler manual recommends..."if possible". The issue is, I cannot get my torque wrench on the nut side to get proper torque on it. 85ft/lbs is recommended for my hull. The JP pistons are in the way and i just don't have the room. My thoughts, if ok to do, is to try to turn the bolts around so the nuts are on the boat side. That would give me great access with my torque wrench to the nuts. It does look like I still may have trouble getting the 4 1/2" bolts through the JP to the transom. The pistons look like they still may be in the way. I will see when I do it. Any suggestions are welcome.

Thank you

[NixaMan]

Just use a long wrench and tighten them as much as you can. I don't think any of these guys use a torque wrench on the bolts. A lot of guys use a Brass nylon Nut on the Stainless Bolts.

[abianca99]

Now you making me go way out of my comfort zone. LOL. I am one of those guys that feel the need to put a torque wrench on everything. I don't know why...maybe it gives me a feeling of security with things. I tend to be very particular about everything. Sometimes it's annoying though as I drive myself up a wall with minor details. Just the way I am. LOL