RIB max engine size

[Magnum]

I'm looking at a few different options to replace the Williams Jetrib - one of which is the Zodiac Yachtline 340 DL which accepts motors up to 30HP. Some outboard manufacturers list identical size engines with different power outputs, like for example the 747cc Yamaha F30 and F40 4-strokes. So the question is, why shouldn't I bolt on the bigger Yammy? It even weighs less.

 

[Jobs_a_ good_ un]

Have a look at the vailant ribs they have deeper v hulls than the zodiac and handle better at speed www.valiant-ribs.com

 

[Magnum]

http://www.valiant-boats.com/

Don't take the same size engines and have less seats. Light though.

 

[Its_Only_Money]

Because weight isn't the only consideration. The manufacturer's statement is intended to reflect the max advisable power as well as the capability to carry the weight. Bolting on a 40 in lieu of a 30 maximum even though the weight is the same would leave you uninsured I would have thought.

 

[jfm]

Magnum, imho always exceed the manufacturer recommendation by a third or 50%. They quote poxy safety bla bla figures for beginners. Get at least the 40, even 50 if you can find a light one. I have had loads of outboard boats and exceeded the manufacturer limit, including currently a runabout with a 125 when the manufacturer says 85. Yeah you void the warranty but who gives a stuff about that. If you overcook it and stress crack the transom (unlikely with a 40), put it down to experience. But at least you have fun in the meantime, and anyway you only use WOT when you judge it suitable

It's a bit like 4door saloons. Most people probly say max 200bhp. Not 507bhp... You coulda had 60hp on the S400, with care

Weight probably matters most here but if you can get it in the right weight I'd stick with Yam or Merc. Much higher quality than a lot of the others, imho.

 

[andis]

The power ratings refer to the strength of the transom; weight is not as relevant.
Double skinned-hull ribs (like the zodiac) can have their transoms supported after-market with pillars in order to accept significantly more horsepower.
Single skinned hull boats (like the valiant and suzumar) cannot have this done as the pillars have nowhere to be bolted without making holes on the hull - which is not a good idea...

Have you considered catamaran ribs (like the Dux the Zapcat, or others)? The are really fast with little horsepower, have huge internal volume and are more stable, both at rest as you move about and while traveling in big seas.