Reply
 
Thread Tools Search this Thread
 
Old 11 September 2021, 16:23   #1
Member
 
Country: UK - England
Town: bedlington
Length: no boat
Engine: 25hp
Join Date: Sep 2021
Posts: 11
25HP motor.... what size boat???

evening all.

i am looking to get myself a SIB. i currently have a small fishing boat (reiver) but where i have it takes two of us to get it in the water ( taking from boat yard with tractor over beach etc... you know how it goes) for this i have a 25hp mercury which i want to utilise for a SIB.

what would you guy recommend as a minimum size/floor SIB to allow me to safely utilise the 25HP?

most i have looked at under 4m say 20hp max. is this a arse covering from the manufacturers. do any of you run a 25 hp on the likes of a honwave 38ie?

would yous recommend an ali deck over a air deck?
__________________
steve jones is offline   Reply With Quote
Old 11 September 2021, 17:12   #2
Member
 
Country: UK - England
Town: Nottinghamshire
Make: Ranieri 15
Length: 4m +
Engine: Suzuki DF50
Join Date: Jul 2016
Posts: 1,281
Quote:
Originally Posted by steve jones View Post
what would you guy recommend as a minimum size/floor SIB to allow me to safely utilise the 25HP?
You don't say if it's an older 2 stroke or newer 4 stroke. 4 strokes gain a third cylinder and weight penalty at this hp.

You may not find this helpful but the manufacturers state the maximum safe horsepower for a reason. Some have overpowered their SIB's/RIB's but you're on dodgy ground regarding insurance and will have an unbalanced stern heavy boat that can bite you unexpectedly.

Overpowering a 20hp transom by 5hp is a 25% increase and obviously more critical than if you were overpowering a 50hp transom where it would only be 10% over.

The aluminium floor will be better to avoid the rippling floor effect, be prepared for the extra weight and setup time regardless of what engine you use, many with this weight craft decided to trailer the boat. Also ~65kg engine weight IMHO is beyond safe lifting by one person. 20hp/45kg is hernia inducing.

__________________
Limecc is offline   Reply With Quote
Old 11 September 2021, 17:19   #3
Member
 
Country: UK - England
Town: London
Boat name: Pip
Make: Excel Volante 330
Length: under 3m
Engine: Suzuki DF6A
Join Date: Jun 2020
Posts: 192
Quote:
Originally Posted by steve jones View Post
evening all.



i am looking to get myself a SIB. i currently have a small fishing boat (reiver) but where i have it takes two of us to get it in the water ( taking from boat yard with tractor over beach etc... you know how it goes) for this i have a 25hp mercury which i want to utilise for a SIB.



what would you guy recommend as a minimum size/floor SIB to allow me to safely utilise the 25HP?



most i have looked at under 4m say 20hp max. is this a arse covering from the manufacturers. do any of you run a 25 hp on the likes of a honwave 38ie?



would yous recommend an ali deck over a air deck?


With the used outboard motor market the way it is, it strikes me that you could sell your 25 and get a brand new or nearly new 20, if that was what you wanted.
__________________
“But for just a few quid more we can get the next size up...”
pumpkinking is offline   Reply With Quote
Old 11 September 2021, 17:21   #4
Member
 
Country: UK - England
Town: Retford
Boat name: Spy-sea-one
Make: Excel 435
Length: 4m +
Engine: Suzuki Outboard/25/4
Join Date: Oct 2011
Posts: 7,532
RIBase
I run a 25h on my excel 435 copes with ease
__________________
jeffstevens763@g is offline   Reply With Quote
Old 11 September 2021, 17:34   #5
Member
 
Country: UK - England
Length: 3m +
Join Date: May 2021
Posts: 696
Is your thinking to end up with a boat that you can hand launch and set up so as to avoid the tractor? If so then you might find you still need two people as your 25 could be quite heavy?
__________________
TmMorris is offline   Reply With Quote
Old 11 September 2021, 17:39   #6
Member
 
Country: UK - England
Town: N. Devon
Boat name: (Not Another) Nutkin
Make: Highfield
Length: 6m +
Engine: Outboard, Honda 135
MMSI: 232036183
Join Date: Dec 2008
Posts: 2,046
RIBase
I used to run a Yam 3.83 with a 25 hp on the back. Great fun and just inside the manufacturers limit.......
__________________
Andy

Bude Dive Club - www.budediveclub.co.uk
GAFIRS - www.gafirs.org.uk
treerat is offline   Reply With Quote
Old 11 September 2021, 17:40   #7
Member
 
Country: Canada
Town: Saskatoon
Boat name: spitfire
Make: Avon
Length: 4m +
Engine: Outboard petrol 15hp
Join Date: May 2021
Posts: 8
Hi, I bought a used Avon 4.0Spitfire RIB, Size 4 Meters long, or 13.3 feet. It had a max rating of 25 hp. Now I'm not sure if that is for 4 cycle but definitely 2 cycle when talking about weight of the motor. AS 4 cycles are of course heavier. Hope that helps a bit ?
__________________
Alsgontrvln is offline   Reply With Quote
Old 11 September 2021, 17:51   #8
Member
 
Country: UK - England
Town: bedlington
Length: no boat
Engine: 25hp
Join Date: Sep 2021
Posts: 11
Quote:
Originally Posted by Limecc View Post
You don't say if it's an older 2 stroke or newer 4 stroke. 4 strokes gain a third cylinder and weight penalty at this hp.

You may not find this helpful but the manufacturers state the maximum safe horsepower for a reason. Some have overpowered their SIB's/RIB's but you're on dodgy ground regarding insurance and will have an unbalanced stern heavy boat that can bite you unexpectedly.

Overpowering a 20hp transom by 5hp is a 25% increase and obviously more critical than if you were overpowering a 50hp transom where it would only be 10% over.

The aluminium floor will be better to avoid the rippling floor effect, be prepared for the extra weight and setup time regardless of what engine you use, many with this weight craft decided to trailer the boat. Also ~65kg engine weight IMHO is beyond safe lifting by one person. 20hp/45kg is hernia inducing.

its a 1990s 25hp 2 stroke. i would be looking to trailer it if i went for an ali deck

thanks for the overpowering bit. makes sense when its said like that... 25% is alot
__________________
steve jones is offline   Reply With Quote
Old 11 September 2021, 17:55   #9
Member
 
Country: UK - England
Town: bedlington
Length: no boat
Engine: 25hp
Join Date: Sep 2021
Posts: 11
Quote:
Originally Posted by pumpkinking View Post
With the used outboard motor market the way it is, it strikes me that you could sell your 25 and get a brand new or nearly new 20, if that was what you wanted.
only issue is the engine i have i am halfs with a pal. so selling wont be an option as still need the 25hp for other boat
__________________
steve jones is offline   Reply With Quote
Old 11 September 2021, 18:26   #10
Member
 
Country: UK - England
Boat name: Redneck
Make: Excel
Length: 3m +
Engine: 20 efi & 9.8 2s
Join Date: Jul 2020
Posts: 3,477
You don't say if your 25hp is a short or long shaft.
If it's a long shaft I think you will struggle finding a suitable SIB.
__________________
Steve509926 is offline   Reply With Quote
Old 11 September 2021, 19:08   #11
RIBnet admin team
 
Fenlander's Avatar
 
Country: UK - England
Town: Cambridgeshire
Boat name: Nimrod II
Make: Aerotec 380
Length: 3m +
Engine: Yam 15 Tohatsu 9.8
Join Date: Nov 2007
Posts: 8,971
>>>where i have it takes two of us to get it in the water ( taking from boat yard with tractor over beach etc... you know how it goes) for this i have a 25hp mercury which i want to utilise for a SIB.

Hi and welcome to the forum.

You may well find by the time you've found a size of SIB that takes a 25hp added to the weight of the 25hp and 25l of fuel in a tank plus kit then that too will be a two man job to launch.
__________________
Fenlander is offline   Reply With Quote
Old 11 September 2021, 19:19   #12
Member
 
Country: UK - England
Town: bedlington
Length: no boat
Engine: 25hp
Join Date: Sep 2021
Posts: 11
Quote:
Originally Posted by Steve509926 View Post
You don't say if your 25hp is a short or long shaft.
If it's a long shaft I think you will struggle finding a suitable SIB.
I have both but the one going on sib will be short shaft
__________________
steve jones is offline   Reply With Quote
Old 11 September 2021, 19:28   #13
Member
 
Country: UK - England
Town: bedlington
Length: no boat
Engine: 25hp
Join Date: Sep 2021
Posts: 11
Quote:
Originally Posted by Fenlander View Post
>>>where i have it takes two of us to get it in the water ( taking from boat yard with tractor over beach etc... you know how it goes) for this i have a 25hp mercury which i want to utilise for a SIB.

Hi and welcome to the forum.

You may well find by the time you've found a size of SIB that takes a 25hp added to the weight of the 25hp and 25l of fuel in a tank plus kit then that too will be a two man job to launch.
I hear you. I will be looking to trailer it. So hopedully that will make it managable for 1 person
__________________
steve jones is offline   Reply With Quote
Old 11 September 2021, 19:52   #14
Member
 
Country: UK - England
Boat name: Redneck
Make: Excel
Length: 3m +
Engine: 20 efi & 9.8 2s
Join Date: Jul 2020
Posts: 3,477
A couple of suggestions :-

Excel Volaire 390

Excel Vangaurd XHD395
__________________
Steve509926 is offline   Reply With Quote
Old 11 September 2021, 19:55   #15
Member
 
Country: UK - England
Town: Retford
Boat name: Spy-sea-one
Make: Excel 435
Length: 4m +
Engine: Suzuki Outboard/25/4
Join Date: Oct 2011
Posts: 7,532
RIBase
Quote:
Originally Posted by steve jones View Post
I have both but the one going on sib will be short shaft
Just for info some manufacturers at around 4m go to long shaft excel still go short on the 435 vanguard. usually when tube dia is at 500mm they go long shaft but excel are short shaft.
__________________
jeffstevens763@g is offline   Reply With Quote
Old 11 September 2021, 20:28   #16
Member
 
Country: UK - England
Town: Nottinghamshire
Make: Ranieri 15
Length: 4m +
Engine: Suzuki DF50
Join Date: Jul 2016
Posts: 1,281
These guys have overpowered their Ribs, the 3.5m/40hp is chine walking doing 35kn one-up flat out and the 3.7m Grand (max 30hp) which has a 50hp Honda is a few knots faster nearer 40kn.
__________________
Limecc is offline   Reply With Quote
Old 11 September 2021, 20:28   #17
Member
 
Country: UK - England
Town: Hinckley
Boat name: Lateral Flow
Make: Excel Virago 420
Length: 4m +
Engine: Outboard 50hp
Join Date: Aug 2021
Posts: 16
If I were you I’d also consider the F-Ribs if using this engine. They are more money but will perhaps handle the extra hp, and make for a more rigid performer.

They are also portable/fold up for storage/transportation, would be ok on a trailer, and yet still light enough for launching wheels etc.

It’s just a thought… have a look. I think their website is F-RIB | Revolutionary new Foldable RIBs (F-RIBs)
__________________
hinckley_steve is offline   Reply With Quote
Old 11 September 2021, 20:41   #18
Member
 
Country: UK - England
Boat name: Redneck
Make: Excel
Length: 3m +
Engine: 20 efi & 9.8 2s
Join Date: Jul 2020
Posts: 3,477
Quote:
Originally Posted by Limecc View Post
These guys have overpowered their Ribs, the 3.5m/40hp is chine walking doing 35kn one-up flat out and the 3.7m Grand (max 30hp) which has a 50hp Honda is a few knots faster nearer 40kn.

"what would you guy recommend as a minimum size/floor SIB to allow me to safely utilise the 25HP?"

A serious question deserves a serious answer.
__________________
Steve509926 is offline   Reply With Quote
Old 11 September 2021, 20:50   #19
Member
 
Country: UK - England
Town: Nottinghamshire
Make: Ranieri 15
Length: 4m +
Engine: Suzuki DF50
Join Date: Jul 2016
Posts: 1,281
Quote:
Originally Posted by Steve509926 View Post
"what would you guy recommend as a minimum size/floor SIB to allow me to safely utilise the 25HP?"

A serious question deserves a serious answer.
I've said already. I don't recommend going over the manufacturer's rating. There's no definite answer if you are going to do it anyway, the bigger the safer, something like a heavy T40.
__________________
Limecc is offline   Reply With Quote
Old 11 September 2021, 20:56   #20
Member
 
Country: UK - England
Boat name: Redneck
Make: Excel
Length: 3m +
Engine: 20 efi & 9.8 2s
Join Date: Jul 2020
Posts: 3,477
Quote:
Originally Posted by Limecc View Post
I've said already. I don't recommend going over the manufacturers rating. If you are going to do it anyway, then the bigger the safer, something like a heavy T40.
__________________
Steve509926 is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off




All times are GMT. The time now is 11:50.


Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.