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Thread: TRIM TAB on jet BOAT

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    Default TRIM TAB on jet BOAT

    Anybody have experience with these I just purchased some trim tabs by nauticus for my 1852 alweld with a 70/50 jet. I noticed in the instructions they screw them on the transom.
    question is wouldnt bolts work better? has anyone ever used these? any help would be greatly appreciated

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    Quote Originally Posted by wiso_67 View Post
    Anybody have experience with these I just purchased some trim tabs by nauticus for my 1852 alweld with a 70/50 jet. I noticed in the instructions they screw them on the transom.
    question is wouldnt bolts work better? has anyone ever used these? any help would be greatly appreciated
    On an all alunimum boat use stainless nuts/bolts and a marine sealant, like 3M 5200 to complete the installation. Keep an eye for any flex where they mount to ensure you do not wind up with cracks. If you do see flex put in a plate to spread out the load at the mounting point.

    So why the need for the tabs? I have never use those nor have I installed them. I know of a few that have them on Fiberglass boats and they seem to work well. I have put Bennett Sport tabs on a lot of inboard jets. The reason they needed them was the only place to carry a load was at the back of their boat.

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    I am getting the tabs because I want to be able to get on step a bit quicker and there is alot of weight on the back of the boat. hopefully they will work out.

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    Quote Originally Posted by wiso_67 View Post
    I am getting the tabs because I want to be able to get on step a bit quicker and there is alot of weight on the back of the boat. hopefully they will work out.
    The only issue I see is, after reading more about them, is that if you ever go aground and the boat goes sideways you risk damaging them. Just remember to get them up and out if you have too. Like have a premade strap/hook or something to put over the edge and be able to pull them up. Also see if you can mount them a little higher (about 1/4" to 1/2") then called for by the instructions

    The reason I liked the Bennett sport tabs is they were longer then they were wide allowing me to mount them a little higher as to be able to get them out of the way in the event of grounding.

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    Did you buy the "smart tabs"? I think they are the ones that have a shock or spring to provide steady pressure down?
    It seems to me they have some adjustment once you have them installed.
    I would recomend you mount them so they have a minmum down angle when you intially install them on the transom. If you mount them with very much of a angle they will most likely have a tendency to push the bow down, you will lose speed and could induce some "bow steering".

    IMO trim tabs on a jet boat are compenstating for other problems.
    You mentioned it is heavy in the rear, have you tryed reposisitioning the load? move battery forward? move fuel tanks forward? move console forward. Changing Those items can take some time but will most likely produce better results in the end.

    Other probs with tabs on a riverboat as spinner pointed out.
    I think Akshrop had a set of those on his 18 foot G3, give him a poke and get his opinion..............

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    They are hydrolic and I did the load thing adjustment thing. My buddy has a set on his 16ft boat and he says they help him get up quicker. I found some older posts all say positive results, pods on the back would be another option but are a bit spendy.

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    If a jetboat with trim tabs is being used like a jetboat then the trim tabs would not last five minutes. I would switch to a prop before I installed a set as they would just get wiped out..

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    In reading these postings, I see a few misconceptions out there so I will try to clear them up. I recently installed smart tabs on my 18 foot G3 with Yamaha 65 outboard jet drive. The installation on this boat requires the screws, not bolts because there is no access on the forward side of the transom to put nuts on bolts. The screws are holding just fine and have a ton of holding power. The tabs are not hydraulic instead have spring force that holds them down initially but allows them to retract to the up position once you are on the step.
    Performance wise the boat no longer needs a lot of weight to be put up front like it used to. I had to carry 4 five gallons jugs up front to keep it from porpoising but now it is rock steady without them. IT also leaps up on the step much quicker than before.
    When cruising the tabs are in the level position so they are not limiting your shallow water operation at all. You have full capability. My boat has a tunnel hull and I find that I can go across any shallow area that the hull will cross depending on how much load I am carrying.
    Another misconception about them is that the angle is adjustable. Not really, the angle stays the same but you can adjust the down force on them with the different mount locations.
    I highly reccomend them for any riverboat.

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    Quote Originally Posted by Rich_in_AK View Post
    In reading these postings, I see a few misconceptions out there so I will try to clear them up. I recently installed smart tabs on my 18 foot G3 with Yamaha 65 outboard jet drive. The installation on this boat requires the screws, not bolts because there is no access on the forward side of the transom to put nuts on bolts. The screws are holding just fine and have a ton of holding power. The tabs are not hydraulic instead have spring force that holds them down initially but allows them to retract to the up position once you are on the step.
    Performance wise the boat no longer needs a lot of weight to be put up front like it used to. I had to carry 4 five gallons jugs up front to keep it from porpoising but now it is rock steady without them. IT also leaps up on the step much quicker than before.
    When cruising the tabs are in the level position so they are not limiting your shallow water operation at all. You have full capability. My boat has a tunnel hull and I find that I can go across any shallow area that the hull will cross depending on how much load I am carrying.
    Another misconception about them is that the angle is adjustable. Not really, the angle stays the same but you can adjust the down force on them with the different mount locations.
    I highly reccomend them for any riverboat.
    Misconceptions....? I suppose, do they not have several locations to bolt the arm to?
    Sounds like you have yours set right, I have seen them mounted up where there is what seems to be an excessive angle pointing down and back, I suspect that could induce some bow-steering........

    G-3's seem to be prone to porposing, I would think a 5 degree transom wedge to get the bow down would a better solution.

    http://www.marineengine.com/products...php?in=1940420

    As Crumm mentioned they (trim-tabs) could get torn off pretty quickly.

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    More misconceptions Gramps.

    There is only one correct place to put them on the boat . the directions have you measure out the exact location, On some boats you may be able to gain access on both sides of the transom at that location, on mine you cannot.

    The down angle is only present at rest. As I said almost immediately on throttle up the tabs go to the level position and have no affect on steering.

    A wedge would be present at any speed thus affecting the speed with increased drag, whereas the trim tab actually improves top speed slightly because at high speed it is no longer hanging down where the wedge would be.

    I can see where the tab might be damaged if you find some way to abuse it, but under normal operation it is safe from damage.

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    Quote Originally Posted by Rich_in_AK View Post
    My boat has a tunnel hull and I find that I can go across any shallow area that the hull will cross depending on how much load I am carrying.
    I suppose if the hull will cross it without touching they would be fine. What about sliding sideways across a gravel bar? Jumping over logs and beaver dams? At some point they are going to hit and get mangled otherwise you would be fine with a prop.

    Have you tried triming the motor?

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    Quote Originally Posted by Rich_in_AK View Post
    More misconceptions Gramps.


    The down angle is only present at rest. As I said almost immediately on throttle up the tabs go to the level position and have no affect on steering.

    A wedge would be present at any speed thus affecting the speed with increased drag, whereas the trim tab actually improves top speed slightly because at high speed it is no longer hanging down where the wedge would be.
    1st off I am glad they are working for you.....those tabs require water pressure to hold them level. Once you are slowed to a no plane speed they will start to drop. In a slide you are going to lose water pressure under the tabs and they are going to drop. Grounding, they are going to be hard aground. If you pull the bow around you are going to quite possibly damage/bend the tabs. Many time I pull the bow around 180* and let the water's current to help me get out. Using a parachute to have the current pull you out backwwards is going to have those tabs making trenches unless you have a way to hold them up. IMO

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    Quote Originally Posted by Rich_in_AK View Post
    More misconceptions Gramps.

    There is only one correct place to put them on the boat . the directions have you measure out the exact location, On some boats you may be able to gain access on both sides of the transom at that location, on mine you cannot.

    The down angle is only present at rest. As I said almost immediately on throttle up the tabs go to the level position and have no affect on steering.

    A wedge would be present at any speed thus affecting the speed with increased drag, whereas the trim tab actually improves top speed slightly because at high speed it is no longer hanging down where the wedge would be.

    I can see where the tab might be damaged if you find some way to abuse it, but under normal operation it is safe from damage.

    Ok..........? There certainly is a correct location, however I have seen them installed by shops incorecctly, so was only trying to stress the importance of getting it right.

    I would presume if someone installs these himself, he would be able to identify if the could use a through bolt or a screw. In some boats that material can be thin and if accessible, a through bolt would provide a better anchorage................................

    As far as the wedge goes, it would allow the motor to trim farther forward, and perhaps mistakenly I was presuming this boat had power trim...........? If so then the trim can be adjusted on the fly. I am confused about your comment on the wedge "hanging down'? The wedge would never be in the water unless you sink the boat.............?

    However the wedge would most likely not get the boat on step any quicker, it does allow more bow trim for boats that have a"bow high attidtude" when on step, such as the G-3.

    I know trim tabs work and understand their function, I myself have a jet boat because I do take it places where there it can be shallow................so much so that I ocassionally get er stuck............

    When that happens the trim tabs could very likely get damaged..................
    Maybe you are one of those exceptional boat drivers that never does that..!........But when it happens I darn sure wouldnt call it abuse..........

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    Quote Originally Posted by Crumm View Post
    I suppose if the hull will cross it without touching they would be fine. What about sliding sideways across a gravel bar? Jumping over logs and beaver dams? At some point they are going to hit and get mangled.
    Dang it Crumm, thats just downright abuse................you should know better.........!!!!!!!!!!!!!!.

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    Quote Originally Posted by Akgramps View Post
    Dang it Crumm, thats just downright abuse................you should know better.........!!!!!!!!!!!!!!.
    I know it but for me it is standard operating procedure.

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    does that wedge apply to inboard or outboard jets? sorry to interupt, but my boat has a light bow attitude and tends to porpose on occasion when loaded in the back. thanks in advance

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    Quote Originally Posted by sevenmag View Post
    does that wedge apply to inboard or outboard jets? sorry to interupt, but my boat has a light bow attitude and tends to porpose on occasion when loaded in the back. thanks in advance
    outboard only........Maybe you can get trim nozzle for your IB..........?

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    I would have to concede that if you are the kind of person that jumps logs and runs over exposed gravel bars then tabs are probably not for you ! Maybe a layer of HDPE on the bottom would serve you more.

    Also the kind of wedge I was referring to is a permanent wedge I have seen installed under the end of the boat which does the same thing as a tab but is more permanent.

    My motor has a built in angle for full down position but is adjustable in the up direction thus it will not correct for a light bow to get rid of porpoising. Sounds like the wedge you refer to would change that angle and just might help with that if so.

    From my experience there is no reason to drill holes all the way thru the transom to put in bolts. The screws provided are self tapping sheet metal screws and using the correct drill size as given they are very tight and strong and do not require you to drill thru the transom. It is not something that you need to be concerned about really. Although I admit I had to build up my wrist muscles to get them screwed in place.

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    Quote Originally Posted by Rich_in_AK View Post
    I would have to concede that if you are the kind of person that jumps logs and runs over exposed gravel bars then tabs are probably not for you !

    I had to build up my wrist muscles to get them screwed in place.
    Only way to get where I want to go is over gravel bars and logs. If I wanted to stay in the deep stuff I would have a prop.

    Before installing screws in aluminum coat them with grease. Makes them go in much easier and are less prone to beak off when you are twisting them.

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    Quote Originally Posted by sevenmag View Post
    does that wedge apply to inboard or outboard jets? sorry to interupt, but my boat has a light bow attitude and tends to porpose on occasion when loaded in the back. thanks in advance
    What Jet do you have? If it is a 212 turn the nozzle over. It is only a couple of degrees but it does make a huge differance. My NR use to plow/bow steer. I turned it over and it now runs bow high and does porpoise a little when I get up over 45 MPH depending on load.

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