How fast 15hp on a 11' rib?

[ALEXSAILS]

I need to know how fast will a 15 hp yamaha outboard will move a 11' rib at 125lbs??? which is the maximun rating hp rating for the rib im thinking of buying....

Im still not sure if I should buy a 9.5' or a 11' rib for the 15hp I have!

thanks!

[codprawn]

I have a Quicksilver 3.1m(10.1') with a Suzuki 15hp 4 stroke - it is not a RIB but has a soft bottom with an inflatable keel. The boat has wooden floorboards to make it more rigid. The boat will do almost 25mph with 3 adults on board - very pleased with it. 9' is a bit small - go for the bigger one. What make RIB is it?

[J S]

I have a zodiac 340 (3.4metres) and i can get 23 knots out of it. Its great fun. But its not a rib

James

[ALEXSAILS]

Thats it!!! a Zodiac 340S the Zoom or the Cadet,,still havent decided...

J S: So u believe a 2 stroke 15ph will be enough for three adults?

codprawn: How do u transport the 4 stoke? I hear they can't be rested or layed down due to teh oil in the pan...???

thanks!

[J S]

Originally Posted by ALEXSAILS

Thats it!!! a Zodiac 340S the Zoom or the Cadet,,still havent decided...

J S: So u believe a 2 stroke 15ph will be enough for three adults?

codprawn: How do u transport the 4 stoke? I hear they can't be rested or layed down due to teh oil in the pan...???

thanks!

Mine is the 340 Acti-V

My Honda is a 15hp 4 stroke. i Has to be layed down on its side but it is no real difficulty. I think a 15 is fine for 3 adults because i have had 5 young adults in mine and it still planes and then goes some. But i don't think 3 adults in this size of boat will be comfortable for a long period of time.

James

Here are some pictures.

[ALEXSAILS]

Wao thanks for the pics!!! Now I can't decide between the air or the wood panel floor of the Cadet 340.

The air floor is lighter and softer and the wood panel floor gives more overall rigidity and is heavier...

I plan to use it here in Puerto Rico and sorounding islands (US and British virgin islands) where the seas are rough and for long distances.

What is ure experience between both??? Anyone....

[J S]

I have found the air floor to be very confortable but if you are carrying any heavy loads like dive equipment a solid floor is the way to go. The solid floor models do hot have as great V as the air floor model though, something to consider.

James

[ALEXSAILS]

Even though the wood floor models dont have an agresive V,,, my thoughts are that the air floor deflects a bit when pounded from underneath by the waves and looses some of its V effect....making it have less of a V than the wood floor system....

Did I explain myself right???

[J S]

Originally Posted by ALEXSAILS

Even though the wood floor models dont have an agresive V,,, my thoughts are that the air floor deflects a bit when pounded from underneath by the waves and looses some of its V effect....making it have less of a V than the wood floor system....

Did I explain myself right???

Yes i can see where you are coming from but when the floor is inflated to the correct pressure it stays extremly rigid and keeps the formation of the V if only flexes very slightly when you hit a really big wave.

James

[ALEXSAILS]

Would u say the added weight of the wood panel floor will give less performance out of the 15hp engine compared to the lighter air floor in the same model inflatable?....regardless of the V design of each...

In other words should my decision be based on how weight will affect performance in the water with same hp?

[J S]

I would say there is quite a bit of difference between the two. The Fastroller weighs 36kg and the Cadet weighs 52kg. Also from my personal experience i can easily lift my boat from the bow and wheel it around for short distances but i tried doing this on a simlar sized aluminium floored boat and i could hardly lift it from the bow.

James

[codprawn]

My Quicksilver has a wooden floor and is rated at 15hp - the same model with an air floor is rated to 10hp. I would say it all depends on how you transport it - on a roofrack or trailer stick with a solid floor - if you need to roll it up every trip choose the air.

You are right that 4 strokes don't really like lying on their side - some are worse than others. It all depends on how long you leave it before strating the engine - my suzuki will smoke a bit at first if it's been on it's side for a while so oil is obviously getting to the plugs.

The 4 stroke is quite a heavy lump but very smooth and quiet - also hardly uses any fuel. I would prefer a 2 stroke though - for the same weight you could have a 20 or even 25hp!!!

[J S]

Originally Posted by codprawn

You are right that 4 strokes don't really like lying on their side - some are worse than others. It all depends on how long you leave it before strating the engine - my suzuki will smoke a bit at first if it's been on it's side for a while so oil is obviously getting to the plugs.

Does the Suzuki have a designated side to lay it down on. Because with my engine if you store it on the right side it starts fine, no different to being stored upright.

James

[ALEXSAILS]

ok im going for the 11' 340... I need the wood floor since Ill be carrying gear and need the stability. The boat will be carried always inflated on the bed of my pick up (6' bed which means ill have 5' hanging back with a flag) no biggie

I already have two small trailers one for a 15' monohull sailboat and another for my 16' hobie cat....cant have another trailer period!

Next questions:
Will the 125lbs cadet be too heavy to carry to and from the bed of my truck by two people??

Can I fit a 25hp into a 15-20hp max rated boat???

thanks!

[codprawn]

Originally Posted by J S

Does the Suzuki have a designated side to lay it down on. Because with my engine if you store it on the right side it starts fine, no different to being stored upright.

James

Yes it does - but as I said you get some smoke on startup unless you wait about 1/2 hr.

[codprawn]

Originally Posted by ALEXSAILS

ok im going for the 11' 340... I need the wood floor since Ill be carrying gear and need the stability. The boat will be carried always inflated on the bed of my pick up (6' bed which means ill have 5' hanging back with a flag) no biggie

I already have two small trailers one for a 15' monohull sailboat and another for my 16' hobie cat....cant have another trailer period!

Next questions:
Will the 125lbs cadet be too heavy to carry to and from the bed of my truck by two people??

Can I fit a 25hp into a 15-20hp max rated boat???

thanks!

Engine WEIGHT is the main criteria - if you can get a 25hp 2 stroke for the weight of a 15hp 4 stroke go for it. I think the Yam 25hp is the same engine as the 20 anyway.

As to moving the boat around what you need are these wheels or similar - people say things are more expensive in Britain but these wheels look overpriced to me - shop around!!!

http://www.allinflatables.com/shoppi...om/wheels.html

Here is a pic of my boat with the wheels attached - make sure you get the large inflatable tyres - not the solid ones. The wheels just swing up out of the way when you aren't using them. They are essential....

[ALEXSAILS]

So a 25hp mounted on a 15hp rated boat will not cause me any trouble,,,transom ripping out of boat or Coastguard giving me a fine for overpowering the vessel?

[codprawn]

Originally Posted by ALEXSAILS

So a 25hp mounted on a 15hp rated boat will not cause me any trouble,,,transom ripping out of boat or Coastguard giving me a fine for overpowering the vessel?

Depends on your coastguard. As to the transom you have this wonderful control called a throttle - use it wisely!!!

[ALEXSAILS]

Ok...Ive made my mind Ill stick with the 15hp and the 11' zodiac 340....
I hope the 15hp planes the boat with three adult people.

Havent called zodiac for a quote on this model...
J S: How much did u pay for the active V 340??

[John Kennett]

You should be fine. I used to have a Zodiac MkI GT (3.4m as far as I remember) with a Mariner 15hp. That planed OK with 3 adults on board.

John