I just received my CMC jack plate ???

[bmurray]

I just had UPS deliver my new CMC jack plate and Power Tech UN150 14.25x23" prop. After reading the instalation instructions I'm a bit confused on initial setting. I think I want the adjustment lowered all the way down and then make sure the cav plate is even with the botom of the boat. This is done by selecting 1of3 hole positons. My Charger has a step at the bottom. Should this be my setting or the very bottom of the hull? Also what is a safe water pressure to stay in? I'm sure I will be asking for more help on this issue, so thanks in advance. Any input is appriciated.

 

[Hooty]

Re: I just received my CMC jack plate ???

Does the jack plate have any set-back?<br /><br />c/6<br /><br />Hooty

 

[bmurray]

Re: I just received my CMC jack plate ???

yes I believe 5"

 

[Hooty]

Re: I just received my CMC jack plate ???

I'm not sure murray but I think I would start with the cav plate even or a little above the lowest point of the hull. You probably want to hold off a wait for someone with experiance with a stepped bottom though. I have a tunnel hull with a 6" set-back jackplate and my cav plate is maybe 1" above the bottom of my transom but there's another 8" of hull below that. I don't know what kind of engine you have but my Evilrude 200 has 18 psi of water pressure at wfo.<br /><br />g'luck & c/6<br /><br />Hooty

 

[HowieDean]

Re: I just received my CMC jack plate ???

You aren't going to get the full benefit from the jackplate if you don't have a low water pickup...<br />But here's what you need to do...<br /><br />Park the boat on the levelest spot you can find...<br />Put a level on the botto of the pad... "the lowest part of the boat" and get it level stem to stern...<br />Trim the motor till the prop shaft is also level...<br />This will give the refrence points you need to set the motor where you want it....<br />With stock side water pickups you will want the top of the pickups level with the pad when the plate is full up... "if memory serves CMC has 5 1/2 inches of lift" but check the paper work...<br />You can get a little more hieght buy filling in the top half of the pickup screens with bondo...<br />But again you really need to get a low water pickup "nose cone" to get the most out of the rig... Check with Bob's Machine shop out of Florida...http://www.bobsmachine.com You don't want less the 15 psi of water pressure... With a low water pickup ideal motor hight at full up with be prop shaft level with the bottom of the pad....

 

[Beernutz]

Re: I just received my CMC jack plate ???

I installed a CMC hydraulic jack plate on my boat, and tried to get the cav plate at the same level, relative to the transom. For some reason, the prop ventilates at times. I'm going to lower the motor an inch and see what happens. There's a lot of adjustment holes on that assembly, and there's bound to be a set that works. As far as I know, it's a matter of experimentation, and each boat has to be different. Somebody told me that you raise the motor 1/2 inch for each inch the plate moved it back, but that can't be right from my experience.

 

[bmurray]

Re: I just received my CMC jack plate ???

right now without the jack plate, the cav plate(where my hydrofoils mounted) is above the very bottom of the V. I have read somwhere that the step on the bottom is the reference point for setting the height on this rig. I just don't want to be removing this motor over and over.

 

[bmurray]

Re: I just received my CMC jack plate ???

Here is a link For Charger setups. They are talking about setting the prop shaft 2.5" below the pad. I guess this is the step in the bottom of the transom. Take a look and see what you guys think. <br /><br /> http://www.bassboatcentral.com/chargersetup.htm

 

[Dhadley]

Re: I just received my CMC jack plate ???

Man you are going all out on this deal! <br /><br />See what they are saying about the propshaft? With pad bottom stepped hulls most of the time we dont refer to the cav plate but rather the propshaft location. I think you will find that if you mount it so that at the lowest point the plate is even with the step youll be fine. You will have 6" of travel from there up which will be more than that prop will work at. <br /><br />I guess I should ask - is the jackplate hydraulic?<br /><br />Cool rig. Let us know how you make out!

 

[bmurray]

Re: I just received my CMC jack plate ???

manual plate. This is why it is so inportant to start on the correct hole of the jack plate. Dhadley, if I read you right, I will be mounting it with the adjustment down, and the prop shaft somewhere between the bottom of the hull and the step or pad. Is this what you are telling me? Right now the bottom of the hull is about even with the top of the water pick up screen/hole. Thanks guys for your patience and help.

 

[Skinnywater]

Re: I just received my CMC jack plate ???

bmurray,<br />Doesn't CMC have a tech support line?<br />I'm assuming by your confusion the instructions are unclear.<br />I am planning to purchase the same jackplate you have. Already I've learned from the posts here.<br />I was again assuming and hopeful the jackplate would NOT come predrilled, would have clear instructions and useful tech support.<br /><br />Please share the outcome of your project and your experiences.

 

[Dhadley]

Re: I just received my CMC jack plate ???

The jackplate will mount to the boat using the existing holes. Then mount the motor to the plate so your cav plate is even with or slightly below the step (the cut out - not the pad). <br /><br />You do not have to remove the motor to adjust the height from there. The plate will adjust up higher than that prop will work at, higher than stock water pick ups will work at and high enough you will make changes to the steering. Start low - test slowly - wear your safty gear - have the lanyard hooked up and watch the water pressure.<br /><br />Good luck and keep us informed of your progress!

 

[HowieDean]

Re: I just received my CMC jack plate ???

The folks at CMC are good people... they make a good product.. and they stand behind them... So please don't think there product isn't a good choice... There are a LOT of variable associated with motor hight even with the same hull and motor combo...<br /><br />Like Dhadley said.. if you just unbolt your motor.. bolt the plate on and then put the motor back in the same hole on the trim bracket as when it was bolted to the hull... you will have more then enough adjustment to get you where you want to be...<br /><br />You guys need to quit worring about where the cavatation plate is... it does NOTHING once the boat is on plane.... Prop selection is one of the major factors in this equassion but whe'll talk about that some other time...<br /><br />Where your CAVITATION PLATE is has no meaning what so ever..... <br /><br />The critical thing is where your water pickups are in relation to your pad.. Besure to watch your water pressure... 15psi... gotta have it our you will get steam pockets forming and heat won't transfer....<br /><br />When you take the next step and go to a nose cone with a low water pickup the focus will change and you will start to think about where the prop shaft is in relation to the pad....

 

[Skinnywater]

Re: I just received my CMC jack plate ???

So is anyone experienced in mounting a jackplate for the purpose of switching from an outboard jetpump to prop and back again. <br />Here the adjustment isn't only to fine tune an inch or two but rather, that, AND the need to lower the motor 4-5 inches for the use of a lower(prop) unit. <br />It gets more complicated because of a jetplate that is mounted between the transom and the pump intake. Now with the jackplate having a setback of 5.5" and the likelyhood of running the pump even higher above the bottom of the boat.<br />It's important to keep in mind my motor is mounted to the transom approx. 4" higher then a prop propelled unit.<br /><br />I'm really hopeing CMC has a good technical support......

 

[HowieDean]

Re: I just received my CMC jack plate ???

All you need to do is figure out how far back and how high up you want to go...<br />You have several options....<br />Jackplates come in all sizes and flavors... we run 13 inches of setback on our Allisons.. so getting the motor back far enough to clear the pump isn't going to be a problem...<br />Offset brackets are also available that will give you a pre-set lift of several inches..and then you can bolt your jackplate to the brackets...<br />You can also bolt 2 jackplates together... we do it all the time....Call Chuck Goodman at Marine Dynamics in Benton, LA (318-965-0201) he's a really good Guy and will be more then happy to give you some options....

 

[what200]

Re: I just received my CMC jack plate ???

Hey Howie-<br /><br />whatcha doing over here on the amatuer board?<br /><br />Are you going to make the stockton race?<br /><br />Hope to meet you when I go on the Plum Crazy ride of death.<br /><br />-Hunter

 

[HowieDean]

Re: I just received my CMC jack plate ???

We are going to try to make the race...<br />Hope you have a good Group Health Plan, Liberal Sick leave... and make sure your Life insurance is paided up... Most rational people won't ride with me, and even I don't ride with Crazy....

 

[bmurray]

Re: I just received my CMC jack plate ???

thanks all. I'm clear on the initial setting now. I will let everyone know what happens. I did buy a 30psi water pressure gauge. I will keep it above 15.