4.3mtr...

andreworiordan · 11 November 2007, 17:11

I have a 4.3M inflatable, boat only weighing 114kgs, nice and light, i have a 25hp mariner on her but im thinking of putting a 40hp mariner on, i get around 20kts with the 25 but need a bit more, What do ye think the 40hp will give me? im thinking around 30-35kts.

Also the engine weighs around 75kgs my max engine weight is 85kgs so im good there,However my max engine size is 30hp(2 or 4 stroke)

Im sure it will be fine but what do you think?

For some pics of the boat >>

http://quiksilver430.blogspot.com/

dverstege · 11 November 2007, 19:25

I own a Metzeler and came across this post.
http://www.rib.net/forum/showthread.php?t=4409
This guy has a 70hp on his Metzeler. It's rated for a 30hp and 55kg.
So it's up to you how save is save. ON my rib I'de go up to a 40hp 2 stroke, four's would be to heavy for me.

prairie tuber · 11 November 2007, 19:59

How long do you want your boat to last?

floater · 12 November 2007, 11:05

i might be wrong about this but when i looked in to the Quicksiver a couple of years back i found some confusion over the ratings, and i think that they were de rated from a 40hp to a 30 hp due to the weight issues of a 40 4 stroke i think if you find a pre 2004 430 then it will be rated to 40 and after that they were rated for a 30

cheers Andy

truble · 17 November 2007, 00:25

avon seasport,,60hp yam,,40mph,goes well and with a 60 seems well within its design ,wish it was 100hp rated,,

Channel Ribs · 17 November 2007, 08:32

Quote:

Originally Posted by andreworiordan

... im thinking of putting a 40hp mariner on, i get around 20kts with the 25 but need a bit more, What do ye think the 40hp will give me? im thinking around 30-35kts.

I can say with some authority that you will suffer from diminishing returns and be lucky to get over 30kn out of her.

It is also my experience that they are not all that comfy past about 25kn because of the shallow V. These are superb boats and very good fun/safe but if you want 35kn+ from an inflatable then you could look at the far more chunky 5.3m version of the HDs or one of the twin hull jobbies.

Jimmy C · 17 November 2007, 18:10

i put a 40hp on an inflatable that we normally use a 25hp on. Due to the weight and 'diminishing returns' (malthouse) i only saw 3-4knts faster top speed, plus it was a hell of a lot more uncomfortable. So maxed out ~25knts

hope this helps

jimmy