Yet another tab question.

[Billdc]

I've had my first boat for 3 years and have only had one person who knew more than me on it, i have no idea if this is normal or not. I have a 23' bowrider(5K lb without passengers) with a 5.7L GXi and Duoprop, I can keep it on plane at about 15MPH(GPS) maybe a little less with proper wt distribution. It planes in less than 5 seconds from a standing start. BUT, I don't feel like I can trim the motor up very much at speed, maybe a second or two on the control, the indicator barely moves when I'm cruising and I need to trim almost all the way down for wakes or chop. I am a fair weather boater who occasionally gets caught in a squall or chop. Are trim tabs going to help me at speed/cruising at 35 MPH? I just don't know how much I should be able to trim this OD up. I have trimmed it so far it started to lose traction, boat was slowing down, and that was a fine line from where I normally run.

 

[steelespike]

Re: Yet another tab question.

Just to be sure we are on the same track a duoprop has twin counter rotating props
do you agree?
I would say that ventilation(losing bite) on that setup is very odd.Are the props matched?
I wonder if your drive coupler is slipping.Seems unlikely on a 2007 boat. Perhaps one or more of the props have a spun hub.Again unlikely .Are the props in excellent condition.
Is it possible the outdrive is possibly stuck in a partial up position and not noted on the gauge.I think the bow should come right down when you trim down; perhaps even to a point that it feels unatural.Its highly unlikely that you would be comfortable running at 35 in chop
of any real size.I would think that trimmed down at 20 or 25 might work.
About how far up do you normally run the trim In relation to full up trim?( not trailer setting)Tell us your prop size,wot rpm and speed by gps at best trim.

 

[Billdc]

Re: Yet another tab question.

Sorry about the description about slipping. WOT 5100RPM with a F6 prop set that are in almost new shape at 53MPH. And by almost new I damaged one set and replaced it last year, and the hub/splines looked perfect.
What I meant by slip is it feels like I have the prop is losing traction in the water not spinning on the hub. Looking at the gauge I never get the needle up to the bottom line above the Down. The only time I see it between the lines is when I am trimmed up at idle into shallows. and then there is trailer height above that. I am curious if trim tabs would allow me to raise the OD even higher and help with GPH fuel useage. While I have not checked the angle of the OD on the trailer at normal operating angle, I have had the drive all the way down and it appears to be just past vertical, which I thought would be correct to push the bow down at start up.
Is there a way to adjust the trim gauge???
Yes the duoprop is counter rotating props on the same axis

 

[DFW Miles]

Re: Yet another tab question.

The short answer is no. Trim tabs will not allow you to trim your outdrive up any further. The dash mounted trim gauges are notoriously inaccurate. If you are satisfied with the performance of the boat but want to know where the outdrive is actually trimmed while on plane, make a note of where the needle is while fully trimmed on plane. When the boat is out of the water drop the drive back down to the same mark (assuming you have adequate clearance) and look at how it is aligned with the hull. Ideally the drive should be just past parallel (trimmed up just slightly).

That being said... I have a set of smart tabs on my boat that I love. I'm on plane in under three seconds and never have a problem with the ride of the boat. Good luck!

 

[NSBCraig]

Re: Yet another tab question.

Is the gauge reading right?

Just thinking, I don't know how it works on your drive but on my brother merc XR drives the gauge is just a cable in a tube that gets stuck giving bad readings.