Real world difference between 2.5hp and 3.5hp tender outboard?

[wipe_out]

On paper the 2.5hp and 3.5hp outboards look identical..The only apparent difference is the 3.5hp revs a little higher (is this where they get the extra 1hp?)

What is the real world difference between these two when used on a small (2.2m) inflatable?

Thanks..

 

[Rigger Mortice]

Sometimes (usually?) the smaller one is fixed gear and the bigger one has neutral/forward.

 

[Eyore]

Sometimes (usually?) the smaller one is fixed gear and the bigger one has neutral/forward.

Which makes a huge difference in maintaining ones self respect and dignity

 

[CAPTAIN FANTASTIC]

The real difference between 2.5 and 3.5 hp is 1hp
Also, it uses more fuel because it has a bigger jet and goes faster; I can plane with 3.5, I can not with 2.5.

 

[wipe_out]

... I can plane with 3.5, I can not with 2.5.

That's the kind of real world information I was looking for..

So the extra £100 odd for the 3.5 is probably worth it..

 

[Mistroma]

We have a mariner 3.3HP with a very small tender and it borders on being uncontrollable with only 1 person, great fun though. It flies along and just skips over the water. I doubt there's much difference with 2 people on board as we only run at part throttle. The extra grunt is handy when it's windy but forward/neutral is the most useful feature for day to day use.

It's easy to modify the 2.5HP Mariner to get 3.3HP, just extend the slot for throttle lever and cut a little bit off the throttle slide. No change to jets etc. and only difference remaining is the lack of a neutral position. Pretty good chance that your 2.5 - 3.5HP model can be modified in a similar fashion if you don't need neutral but want extra HP.

 

[Pete7]

Yes, plus the gearbox makes starting and control so much easier.

Pete

 

[CAPTAIN FANTASTIC]

That's the kind of real world information I was looking for..

So the extra £100 odd for the 3.5 is probably worth it..

Very much so; same engine, same weight, more power for less than £100

 

[30boat]

Are we talking four stroke or two stroke?

 

[dartmoor]

Are we talking four stroke or two stroke?

I was wondering that too...

 

[wipe_out]

Talking about 4-stroke..

 

[dancrane]

Just reading the thread out of idle interest...

...from the answers so far, it's extremely hard to see why anybody would buy the 2.5hp, at a saving of only £100. Surprising the company (which is it?) can sell any.

 

[prv]

An intriguing idea. Anyone know if my 2.2 Suzuki 2-stroke can be hot-rodded?

Pete

 

[Tranona]

Just reading the thread out of idle interest...

...from the answers so far, it's extremely hard to see why anybody would buy the 2.5hp, at a saving of only £100. Surprising the company (which is it?) can sell any.

Quite simple. On a 2.2m inflatable the OP has he cannot use the extra hp. It won't make the boat go any faster and probably make it more difficult to handle.

Manufacturers offer the lower hp version because they know there are intelligent buyers around that understand why and are happy to save £100! On the other hand they are equally happy to take the extra £100 of people who don't mind paying for something they don't need.

 

[Rigger Mortice]

An intriguing idea. Anyone know if my 2.2 Suzuki 2-stroke can be hot-rodded?

Not so easy with the Suzuki.
With the Mariner/Mercury/Tohatsu the 2.5hp model is just a detuned 3.5hp engine and the conversion is easy.
The Suzuki 2.2hp does not appear to have a bigger brother

 

[Beyondhelp]

I have a Wetline 230 with a 'modded' Merc 4 stroke 4hp. I'm not really that heavy ~14 stone, and that wouldn't plane with just me on it. however the 4,5,6hp are all the same engine except for carb. So 6hp carb and now it flies. Gets in plane quite easily with just me, not with anyone else however. Its not at all uncontrollable. The only down side is carrying all this by yourself is really quite hard work, its not an amazingly light engine. But ~12mph is quite good fun.

 

[dancrane]

I'm not really that heavy ~14 stone...the 4,5,6hp are all the same engine except for carb. So 6hp carb and now it flies...It's not at all uncontrollable. 12mph is quite good fun.

That's what I was thinking. Even if a bigger (or same but tuned) engine technically offers greater output than the boat can handle, there's no obligation to let rip when half-throttle will suffice...

...so I'm sure I'd rather possess the option to apply more power, even if in practice I never needed it. Buying a virtually identical engine at similar weight that offers 40% more power for only £100 extra, isn't a choice I'd take long to decide.

 

[Beyondhelp]

Quite.. I chose the 4hp as its got a 'proper' gearbox. I also use it as a backup engine on my 17ft boat, so then upgraded it to the 6hp version. It just so happened that it made it really good fun on the tender as well.

 

[simonfraser]

It's easy to modify the 2.5HP Mariner to get 3.3HP, just extend the slot for throttle lever and cut a little bit off the throttle slide. No change to jets etc. and only difference remaining is the lack of a neutral position. Pretty good chance that your 2.5 - 3.5HP model can be modified in a similar fashion if you don't need neutral but want extra HP.

can i do this for my 2.3HP Honda air cooled ?!

 

[Cardo]

Our boat came with a nearly new 2.5hp Mariner. It's fine with one person on our 2.4m inflatable, and in fact struggles as when the dinghy goes up on the plane, the prop can surface (well, the water level is sucked down) and essentially stalls, so one has to delicately control the throttle when getting up to speed. But with two or more people, it feels very underpowered. We don't get anywhere near planing speed and just sit there at full throttle, going nowhere particularly fast. Not bad for short hops to the beach from anchor, but tedious when going a slightly longer distance.

I have read the 3.5 is essentially the same beast, so I may see if I can jig ours up to 3.5hp.