New to me boat

[Ats666]

Hi, I bought an old pontoon from my friends parent a couple of years ago.
​​​​​I can't find a capacity tag anywhere on it and don't want to get into trouble for overloading it going through the locks.
I found the HIN in 2 locations.
QLM120077C888
It's 5.18 meters long.
The registration paperwork I received with it doesn't have mention of it anywhere either.
How would I go about finding out this information?

Next question is about finding out wot rpm range.
It's an early 80s 18hp Mercury that runs perfectly.
The serial number is 7198298
​​​​
I definitely need to install a tach because it sounds like like 3500rpm to my ear maximum.

Thanks
Allan

 

[Scott Danforth]

welcome aboard.

WOT RPM will be in the 5000-5500 RPM range

you need a tach to verify

 

[ahicks]

Lacking a certification tag, common sense would likely rule. E.G. If you're going through with pontoons nearly underwater, you might draw some attention.

 

[wahlejim]

With no scientific background whatsoever, just experience and encountering several pontoons, capacity for weight is usually around 100lbs per linear foot. Doing the conversions to metric, it seems you would be pretty safe at 775-800kg

 

[5150abf]

Find a comparable new boat same size and tube diameter and go with that, it is the same formula even for an old boat.