JIMB

I have a 1990 320 Baja sitting on a tri axle loadmaster trailer
I currently only have about 300 to 350 pounds tong weight
the boat is 7300 to 7600 #'s dry. How far back should I move
the axles to get about 700lb's tong weight. THANKS

boatfreak

Is moving the boat forward not an option? You may not have to move more than a few inches to make a big change in tongue weight.

muffin

I know that they always say 10% of total weight should be on the tongue...however, the coast guard ax. class I took years ago said that as long as you dont have sway problems, 150# should be more than enough. Hope this helps.

JIMB

The boat can not be moved anymore forward. And yes the boat does sway at 65mph or more.

fund razor

Not far at all.

I am with boatfreak.

While I don't have a more specific answer, when you move an object over what is essentially a fulcrum, it doesn't take much.

It's the equivalent of both people on a teeter-totter moving the same direction. (One "in" one "out") the OUT one is gonna have sore rear.

Cord

Unfortinatly, it's not an easy answer. You need to know where the center of gravity of the boat and trailer is. Then you can start measuring and doing the math.

Playing off fund razor's suggestion of a 'teeter-totter', you can find the sweet spot pretty easily. Support the trailer on jack stands with a scale under the tongue. Using a pair of floor jacks you can jack the trailer up. The jack would be the center axle location. Now read the scale and move the jack forwards or back based on the reading. If you don't have a scale that reads 700lbs, you can use a couple of them with a cross beam. Just zero them out after setting the beam and add all the value together for a total tongue weight.

I'd be shooting for 750 to 800lbs tongue load.

ratman

go in small increments...employ the hit or miss method

tpenfield

Measure the distance from the middle axle to the coupler (3 axles?). Then take about 2% of that distance and try that. It should be only a few inches.