Center of gravity

RussGW270

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So, as I am working on the trailer (with the boat off of it), I am curious where, approximately, the “center of gravity” might be on this boat.

The reason I ask is that the roller/winch brace was loose and while I have all new nuts for it, I am wondering if it has moved forward through the years, hence why the tabs are resting on the bunks by 3”....or if the previous owner just never noticed.
Before I cut the bunks, I figured to ask here.

I suspect the center needs to be centered over the axles, but not sure where that might be.

2004 Islander 270 with twin F225 Yams. It tows fine as is, but only takes one time of forgetting the tabs to break them.

Any thoughts?

Thanks!

installing an entire new wiring harness atm plus adding a couple ambler lights to the pvc risers as well as a spare tire mount. Just rebuilt the 2nd axle and replaced the short studs with longer ones.

Will be done with all of it tomorrow and swap back to my trailer Sunday.

This is what it looked like before.

Russ
 

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UCPA111

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I think what you really want to do is put the boat on the trailer and determine tongue weight. I had to set mine on trailer...weigh tongue load...and then adjust. That's the important thing for your towing. Yes...it's some messing around. You may need to shift bunks forward (I did that on mine) to get the load I needed on the tongue of the trailer. Keep in mind your normal loading and fuel.
 

wspitler

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Russ, the CG information is available in chart format from Grady White. You can ask them to send you the latest chart or the one that is most accurate for your year model. Example attached:
 

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SkunkBoat

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For a big rig like that, you should spend the time and do it right. Go to a scale with a full load. Get your real gross weight and real tongue weight (at hitch height). Adjust the tongue weight accordingly.
9-15% is what most will say. Make sure that its below the max rated tongue weigh for your hitch.
Once its done its done.
 
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RussGW270

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Al good points and will be doing it all. I just wanted to see where the center might be as it is kinda hard to cut the bunks if the boat is on it. So, Will, for now, cut 3" off, leave the post where it is, get the boat back on it, and then take it to the scales. If I end up finding it needs the 3" extra, I can always order new bunks and swap them next trip.. but for now, that will at least keep the tabs from being broken if they are not fully trimmed when going in.

Thanks for all the good input.

I'll also contact Grady and get the chart for the specific model, thank you!

Russ
 

glacierbaze

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You usually damage your tabs loading onto the trailer, not unloading. Also, a lot of tabs set ups have auto retract, which raises the tabs when you turn the ignition key off. Does yours?
Cutting your bunks off seems like a strange way to approach the question.
 

RussGW270

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Yea, not sure why anyone would be asking how to cut the bunks so they did not damage them unloading, so not sure where that was from. Also, if the trim tabs are auto or not, which I know they are not, having them rest on the bunks is still a good way to get them broken when it does not work.

I have a plan, thanks.
 

glacierbaze

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“...but for now, that will at least keep the tabs from being broken if they are not fully trimmed when going in.”

Sorry, I took “going in” to mean, going into the water, or unloading.
 
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RussGW270

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No need to be sorry bud... you meant to help. That is 110% good enough for me ;)
And no, not going to cut the bunks, will move them instead as stated. That sounds like a better plan. I moved my PC out to the shop so the kids could use that room for school and only skimmed the notes, so missed that part heh.

R
 

seasick

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I have been happily surprised that there is no political views posted on this forum until now. I am seriously disappointed
 

RussGW270

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I am actually not going to mess with the bunks for now. Decided to wait on them. Just going to leave them as they are till I can weigh... that and I am tired of messing with the trailer today lol.

Added all the stuff to it, just need to hook up the guide lights I added and the running lights that Amazon shipped late..

Everything else is done.

R