Position of pontoon in relation to axles question

[ronboonville]

I have a 24' Nissan pontoon with a 90hp Nissan. Maybe 1986 vintage. It seems like the tongue weight is too much. There are no scales within 40 miles to check it. The trailer it came on is not the original and must have been for a smaller boat as I had to move the bunks out some for a good fit. It appears I might be able to move the tandem axle forward maybe a foot. I probably will try not pulling all the way forward on the bunks next time I take it out and see what difference that makes. My question is "is there rule of thumb measurement in relation to the axles location?" I think I can extend the bunks easier than moving the axle. It doesn't launch all that great, will this help? I didn't carpet the bunks when I replaced them. Do they need to be?

 

[H20Rat]

Just take a SWAG at the weight. Pontoon weight is around 2000 pounds. Engine weight is around 300 (including fuel/oil) Misc gear another 100. Lets just say 2400 ready to go down the road with a battery. Trailer weight is probably around 700-800 pounds, so you are going to be somewhere near 3000 to 3200 pounds.

With a tandem axle pontoon, I'd put 8% or so on the ball, so 250 pounds. Search on hear how to use a bathroom scale to measure that with a board. Unless you have a 'big person' scale, don't drop your jack on it directly!! (you should be able to measure 250 on a bathroom scale directly, but if you suspect it is heavy, use the board method first)

 

[kjsAZ]

you can also slowly crank it down onto the bathroom scale and when it reaches the max it can handle stop and go up again. Then it's time to use the lever method.

Tandem trailers should have 5-7% tongue weight.

 

[H20Rat]

Tandem trailers should have 5-7% tongue weight.

With a regular boat, yes, but pontoons are a little different. They have so much drag high up that they effectively reduce tongue weight while towing at speed. (wind pushing on the top, not on the bottom) Pontoons are also far more affected by side wind gusts. 5% might be safe, but it could also lead to a fun ride at 75 mph.

 

[kjsAZ]

that could be but ahem..... trailer tires are only rated up to 65mph unless you use LT tires if you can find them at the appropriate load rating.......

 

[ronboonville]

Thanks for the info. I saw our bathroom scale in our trash can about 3 weeks ago. will search yard sales. Not worried about speed because I might go as fast as 45 mph.

 

[kjsAZ]

Or you can get a 550lbs spring scale http://www.homedepot.com/p/Buffalo-Outdoor-550-lb-Capacity-Hanging-Food-Scale-MS550/204186473 for $20. That's what I use. A simple "tri-pod" made from a bunch of 2x4's to hang it over the coupler Even if it would fail it wouldn't be a problem as the trailer jack is only a fraction of an inch above ground during measurements.