Explorer 275 2000

[wingtime]

Here is a question.  Which trim tab rocker switch are you pushing to trim out the list?  Remember they are cross wired (they should be anyways).... so if you push the top of the port side switch the starboard side tab will extend.  Also there is a delay in the time for the tab to deploy and then for the boat to react.  Bennett has a great set of instructions on their website on how best to use trim tabs.


Bob,  How do the Bennett trim indicators work?  I mean how do they "know" what position the actuator actually is in?

[Capt. Bob]

Wing,
I realize you are addressing SB but the the indicators are just that, an indication as to the % of the tab position relative to the total travel of the tab. The actuator has a sensor (rheostat) that measures the change in position of the shaft. It's similar to the fuel gauge we all know and love but works much better.

Like the fuel gauge, accuracy (I'm guessing is good) is really secondary to its intent. Rather it's used as a reference point for adjusting your tabs. I use mine on takeoff for the best possible hole shot. After planing, I adjust the tabs via boat attitude (port or starboard list correction) and tachometer reading. My flow scan also comes into play but that's another story.

I find that in calm seas that my best running position is indicated by 4 lit "leds" on port and two on starboard but that can (and often does) differ with changing conditions. Again adjustments are made via visual boat position and engine speed/trim. I'll then look at the lights as a reference point.

[seabob4]

CB, always feel free, after all, we're both Bobs...

Bob is right, basically a percentage of deflection.  However, and Tom may agree/disagree here, I always felt the "old" style trimdicators were not a true representation of where the tabs really were.  After installing and testing 100s of tabs systems, I really knew how long it took for Bennetts to fully extend...and the bar graph and digital readout on the trimdicators always went faster than the tabs were actually moving.  So in that respect, where the tabs are as opposed to where the trimdicators say they are, well, that was subject to debate IMO...

The "new" trimdicators are basically identical to Lencos.  No more digital readout, just a series of lights in a vertical orientation on each side of the switch.  On Lencos, I found this depiction to be MUCH more accurate in regards to true tab position.  I would assume the same on Bennetts, although I have yet to work on a boat with the new style trimdicator.

Bruce is of course correct in regards to how tabs are wired.  The concept behind the switch (people have trouble with this) is NOT what the tab is doing, but what the boat is doing.  That's why the switches are labeled "Bow Down", "Bow Up", not "Port Tab Down", "Port Tab Up".


So all that being said, I wanted to add some things.  The 275 hull was and is a stable platform.  When it was introduced in, I want to say '99, it was the biggest boat by far in the AS lineup that we had seen, as the 270 and the 290 were no longer being built when I started there.  So of course, amongst employees, it got our attention.  Quite a bit of testing was done on the first couple boats before she went into production, make sure the engine heights were right, props right, fiberglass imbalances right, all that good stuff you do with a new boat.  Never did we hear (and we would have heard) about the hull being "tender", about any listing issues, nothing...and we would have heard.  Our good friend here DoubleTrouble (John) is the most vocal of the 275 owners here, and, unless he has a list and has just grown accustomed to it, has never said anything about any listing issues on his boat.  Nor have any of the other 275 owners, at least not that I have read.

It's my opinion, and mine only, that, while adjusting for the list that D'SHOW is experiencing may solve the issue, to me, the adjustments are compensating for something that is inherrantly wrong with his hull.  That's why I asked if he could get any info from the PO (or even the dealer he bought it from, if that's the case) as to how she ran in her previous life.  If the motors have been raised to improve performance (along with the addition of 4-blade props for better bite), well, this COULD have a detrimental effect on handling, so we'll have to wait and hear from D'SHOW as to what holes the engines are mounted in.  If they are 3rd or 4th hole down (maybe even 5th, can't remember how many holes Mercs (Mariners) of that vintage had), then we'll suggest bringing them back up to the 2nd hole (lowering the motors).  If that doesn't fix the problem, then I really feel, as I described earlier, that there is something going on with the hull bottom that is causing the list.

With Farley's boat (and possibly Scotty's 22-2), I can easily see where (2) standard rotators will jack the starboard side up due to the upward thrust of the props rotating CW.  But with CRs, that phenomena would be canceled out.

Of course, I could just be dead a$$ wrong on this one...

[wingtime]

I guess what I was asking is if there is a sender in the actuators that gave you the trim position indication. Sounds like that is the case.

[gran398]

That is true SB, the twin standard rotation engines jack the starboard bow up, portside down.

As Farley says bow roll to either side is easily remedied by trimming up one engine.

[seabob4]

Bruce, the upper portion of the actuator has a coil in it, with a rod protruding down through the center of the coil into the lower portion.  As the rod moves up and down with the action of the actuator, the change in strength of the magnetic field of the coil is what is measured, and translated into a display...at least that's what I draw from the construction.  The rod has "cut" marks so the trimdicator kit can be used with all existing Bennett actuators, you just shorten the rod to fit your actuator..

[wingtime]

Bruce, the upper portion of the actuator has a coil in it, with a rod protruding down through the center of the coil into the lower portion.  As the rod moves up and down with the action of the actuator, the change in strength of the magnetic field of the coil is what is measured, and translated into a display...at least that's what I draw from the construction.  The rod has "cut" marks so the trimdicator kit can be used with all existing Bennett actuators, you just shorten the rod to fit your actuator..

So I could retrofit a indicator to my 245 if I desire.  cool.

[seabob4]

Yepper.  The top of the actuator threads onto the actuator body.  Unscrew the old, screw on the new one (have to enlarge the hole where the hose passes through to route the lead into the boat), and wire it up.  With your HDS-7, you can have the tabs displayed on your head unit...http://www.bennetttrimtabs.com/indicators.php?cID=2

[Capt. Bob]

Yepper.  The top of the actuator threads onto the actuator body.  Unscrew the old, screw on the new one (have to enlarge the hole where the hose passes through to route the lead into the boat), and wire it up.  With your HDS-7, you can have the tabs displayed on your head unit...http://www.bennetttrimtabs.com/indicators.php?cID=2

Unscrewing the old, at times can be difficult but that aside, you will need to drill a separate hole to feed the lead through. IIRC the sensor wire is sealed in the back of the actuator and is rather fragile. The wire will be crushed if you tried to bend it and feed it through the nipple hole. Granted, you could indeed drill a very large hole to span both the nipple and wire or possibly notch the area between the wire and nipple.

Then again, I could be wrong. I'll have to look at an old actuator.

[seabob4]

It's been a while for me CB.  In other words...I can't remember what the backside of the mounting pad looks like!  BTW, do you have the old style or the new?

[wingtime]

With your HDS-7, you can have the tabs displayed on your head unit...http://www.bennetttrimtabs.com/indicators.php?cID=2

That would be totally bitchin' !

[Capt. Bob]

BTW, do you have the old style or the new?

SB,
I'll go out on a limb and say I have the old style based on the fact I purchased them in 96.
The sensor is still the same as the original but as you indicated, Bennett has upgraded the "Trimdicator" indicator. My original was the LCD model and eventually suffered from excessive exposure to the sun (much like its owner).

When I transferred the tabs to the WAC from my CCP, I replaced the indicators with the updated LED model.  The new actuator with the sensor (I broke the wire leads on the originals when removing) fit the old actuator perfect and I'm guessing it's still the same.

That's pretty trick that they can be hooked up to the Lowrance.

[seabob4]

Yeah Bob, you DID have the old style...

I was probably unclear earlier in my reference to Lencos.  With Bennetts, you have a choice of having a separate indicator while maintaining the traditional Bennett rocker switch, or you can get the switch with the indicator built in, which is basically the same as the Lenco indicator switch.

What me personnally would think would be REALLY helpful to a lot of owners is a graphical representation, taken from a side view, of the tabs in relation to the hull.  I think most owners would like to look at a display which is in effect a "picture" of where their tabs are, instead of a number representing percentage of deflection.  One look, and the answer to the question, "I wonder how far extended my tabs are?" would be answered.  JMO, once again...

[D'SHOW]

Well my good Aquasport friends. I chequed the engines and they are mounted on the second hole. But, did notice the bothe engines are mounted 3/4 of an inch towards port from center line. My 270 lists port. Could this be the problem and if it is could it be fixed?

[seabob4]

Well my good Aquasport friends. I chequed the engines and they are mounted on the second hole. But, did notice the bothe engines are mounted 3/4 of an inch towards port from center line. My 270 lists port. Could this be the problem and if it is could it be fixed?

D, one question.  Where did you get your measurement to determine the boat's centerline?  Centerline is ALWAYS determined by measurements taken from the hull, NEVER the deck.