Weight limits for outboards?

I too am having difficulty understanding this post and its premise. Anything can be remotely or digitally controlled and the mass of a drive setup, really doesn't have a lot to do with the size of a vessel, other than some are clearly not well suited, compared to others.

 

The best place for 300 HP outboards is on another boat than yours...I would sell them immediately if I had the luck to find 2 lost poor 300 HP outboards crying for a good new home..
The almost rational applications for such engines is only a few high sport planning boats, made to satisfy the ego of guys with big wallets. It's like the Veyron or Ferrari, sushis wraped with gold leafs, Iphones, Nikes, gold Rolex, one pound gold chains on a hairy chest, gold plated guns with diamonds and nacre and so on. The pimp or narco style so common in Florida.
In fact nobody with marine common sense and some experience will use such engines. Very complicated, expensive and however cooled by sea water, one of the most corrosive liquids of the world, and the a big part of the 300 ponies is lost on a ridiculously small 15" propeller. It's true that makes an impressive foam with a big deep noise. Even better you can put 3 on the stern, so the propeller of the middle does not see any clean water but that makes more foam and roars better.

 

Built for speed, the gearing and prop diameter are far from ideal for a large displacement cat application. Would be suitable for a fast planing cat around 9-10 metres, but even then a 30" shaft would be wise.

 

Mercury does a 115 Bigfoot (165kg) or Command Thrust as they are called now. About $15,000 each over here. I hear they are quite good. I am looking to put a pair of 60hp Bigfoot's (or is that Big feet???) on a 29ft pontoon