55HP on a Quicksilver 4.3 HD XS

Seacidal · 26 January 2009, 14:43

Hello all

I have just recently seen this SIB and thought i have to have it. I know people put 40hp on it, but i would really like to throw on a 55hp Mercury.. which is only bout 23kg heavier tha the 40.

Has anyone done it or knows of one? Hows the performance?
How fast does it go with the 40hp on it? Can te SIB handle it?

I dont want to race or anything like that but i just like to get to my spots real fast

All input is greatly appreciated.... Thanx in advance!

Zane...

jyasaki · 26 January 2009, 16:10

Max HP rated at 30.

Max Engine Wt at 85kg.

I'd say you're planning on living up to your username.

jky

Seacidal · 26 January 2009, 16:17

Hahaha.. u think so??
U know ur a speed junky when...

Anyways these things used to be rated for 40hp then they changed it down to 30hp prolly for liability issues.
so if it still said 40 then u still have that safety margin 10hp extra.

I dunno...nevr owned a SIB or a boat that small for that matter, so just awaiting some input from the SIB pros.

Zane...

Nasher · 26 January 2009, 16:27

Quote:

Originally Posted by Seacidal

Anyways these things used to be rated for 40hp then they changed it down to 30hp

Maybe quite a few years ago when outboards moved from being rated at the powerhead to power at the prop.
Or have I got that the wrong way around?

Nasher

prairie tuber · 26 January 2009, 16:30

I believe the 4.3 HD XS is currently rated for a 30 hp maximum. If I recall, they were at one point rated for a maximum of 40 hp back in the day when everybody did the right thing and used carb'd 2 strokes with them. The reduction to a 30 hp rating is no doubt in response to the heavy 4 strokes that are now on the market. While I don't have any personal experience with this particular boat. It do have experience with a 4.2 m Zodiac with an inflatable V keel (also rated for a max of 40 hp 2 stroke). Their capabilities should be quite similar to each other, so my advice will be based on that experience.

Firstly, an extra 23kg is alot of extra weight to stick on the transom of a boat this size. For a 4.3m SIB with an inflatable V keel (which is not at all like a tunnel hull such as a zapcat/thundercat), a 40 2 stoke will provide all the speed that this hull size & design can safely handle under ideal conditions. In other words, in calm flat water, you'd have decent control of the boat with a 40 hp at WOT, in any kind of chop, you'll need to reduce the throttle to maintain control of a 4.3 m SIB with an inflatable V keel. A 55 would be a complete mismatch for a boat such as this.

spartacus · 26 January 2009, 21:54

I agree with Prairie tuber and jyaski on this one.

The 4.3m Quicksilver (with the aluminium floor) is similar to the 4.2m MkII Futura, but without the oversized sponsons or speed tubes, two key features that give the Zodiac more stability.

Adding an old Mercury or Yamaha 55hp is ill-advised. Apart from the transom being rated for a lower hp engine, you need to see the bigger picture. That extra weight probably doesn't seem excessive on a flat-calm stretch. God - I wish I had more hp for days like that!

However if you hit a wave at the wrong angle with a 55hp at WOT - then you'll know about it.

Sure it'll get you to your spots faster, but better to get there in one-piece is my advice. Your insurance (if you plan to have boat insurance) will walk away from this in the event of an accident, which will be more than can be said for you.

Nos4r2 · 26 January 2009, 22:08

Quote:

Originally Posted by spartacus

However if you hit a wave at the wrong angle with a 55hp at WOT - then you'll know about it.

Yep-and I suspect he'll be lucky not to fold the boat in half and pop the floor out.

Seacidal · 27 January 2009, 06:12

Thanx for all your input fellaz... I think a Zapcat or a thunderbolt is a better match for what i want out of a boat. Im ditching the QS

Whats the thunderbolt website?

Thanx
Zane...

Channel Ribs · 27 January 2009, 08:21

Quote:

Originally Posted by Seacidal

Thanx for all your input fellaz... I think a Zapcat or a thunderbolt is a better match for what i want out of a boat. Im ditching the QS

Good call!

A 4.3m QS would be far too tail heavy and the nose would catch any oncoming air like no body's business!!

codprawn · 27 January 2009, 14:00

Get a Zapcat with a 50hp Tohatsu 2 stroke - you can be as mad as you like then!!!

prairie tuber · 27 January 2009, 14:40

If you want more practicality with near zapcat-like performance, go with a Gemini Surf GRX 4.2m like Ed the Duck has.

Seacidal · 27 January 2009, 19:01

Im glad i didnt rush into it... dont get me wrong it an awsome lookin boat but just not what im lookin for in a boat.

I went fo a Tunderbolt, center console bucket seat with a 90hp on it wooooooooooot

I still have to go and check it out tomorrow.. but i think im gonna just grab it. Its slightly used.

Maybe a dumb question... but can one change its color? like if i wanna make a scheme

Anyways is it a good choice?

Thanx again!!