HP or cc .

[Baggywrinkle]

I looked at a video testing 2.5 HP outboards. And two got a 2.7 meter sib up on plane. The Yamaha and selva. But Honda and Suzuki could not.
Ok. Thank you. I looked at a video testing 2.5 HP 4 strokes , they tested the Yamaha, Suzuki , Honda, and an Italian make. The only two that got the 2.7 meter to plane were the Yamaha and the Italian one.They both had 85cc, the others only had 68 and 57 cc. So the higher cc outboards got the boat to travel much faster.

I wouldn't base your buying decision on whether a 2,5hp engine can get a 2,7m RIB on the plane .... weight distribution has a big effect on getting onto the plane, as does trim, and I certainly wouldn't count on a 2,5hp being able to plane on every dinghy reliably. As a kid I used to tear round the anchorage in an Avon Redcrest with a Seagull on the back and a broom handle stuffed in the tiller handle - I weighed next to nothing but still had to sit well forward to get it to plane.

If planing and speed are important, then around 6hp is what many coastal cruisers opt for as a compromise between weight and power, but if you like to anchor a long way from civilisation and use your tender as a "car" to get places then 10hp + is advisable (as is a bigger tender).

 

[munster1967]

I wouldn't base your buying decision on whether a 2,5hp engine can get a 2,7m RIB on the plane .... weight distribution has a big effect on getting onto the plane, as does trim, and I certainly wouldn't count on a 2,5hp being able to plane on every dinghy reliably. As a kid I used to tear round the anchorage in an Avon Redcrest with a Seagull on the back and a broom handle stuffed in the tiller handle - I weighed next to nothing but still had to sit well forward to get it to plane.

If planing and speed are important, then around 6hp is what many coastal cruisers opt for as a compromise between weight and power, but if you like to anchor a long way from civilisation and use your tender as a "car" to get places then 10hp + is advisable (as is a bigger tender).

Thanks for your reply. Yes a 2.5 is a bit underpowered to plane. I'm watching the weight of the motor and a 6 HP would be far to heavy to lift on and off every trip. It's not so much planing but a higher top speed I'm looking for. Currently my 2 HP dt2 gets me to 9 kmph. Id like to get up to 12 or 13 kmph.

 

[munster1967]

If using for a small yacht tender the most important practical metric is not HP or CC - but KG.

That’s why I prefer (second hand) 2 stroke Tohatsu / Mariner / Mercury 2.5hp or 3.3hp.

The extra fuel used is minuscule with most tenders - 5L of E5 petrol lasts almost a season in my normal use.

Yes agreed , the weight is paramount. I don't use it as a tender but like to go on 2.5 hr excursions on inland waterways. My little Suzuki 2 HP dt2 gets me to 9 kmph and I'd like to get that up to say 12 or 13 kmph for longer trips on the bigger lake. Perhaps a 3.3-3.5 HP 2 stroke might suit better.

 

[Tranona]

Perhaps a 3.3-3.5 HP 2 stroke might suit better.

Maybe but you have not been able to buy them legally for over 20 years so your choice of old ones might be a little restrictive.

 

[munster1967]

Maybe but you have not been able to buy them legally for over 20 years so your choice of old ones might be a little restrictive.

Yes indeed. It's difficult to find a good one.

 

[Boathook]

Maybe but you have not been able to buy them legally for over 20 years so your choice of old ones might be a little restrictive.

If your knackered 4 stroke happens to pack up in Alderney, Mainbrayce chandlery can quite often can replace it with a 2 stroke so that you can continue enjoying your holiday.

 

[Tranona]

If your knackered 4 stroke happens to pack up in Alderney, Mainbrayce chandlery can quite often can replace it with a 2 stroke so that you can continue enjoying your holiday.

not sure that will help the OP who uses his boat on canals and lakes. Also i am not sure they will still do that in Alderney and you run the risk of importing it illegally into the UK. would ove to know how many people have actually done that in recent times - but of course they are unlikely to admit to an illegal act.

 

[Boathook]

not sure that will help the OP who uses his boat on canals and lakes. Also i am not sure they will still do that in Alderney and you run the risk of importing it illegally into the UK. would ove to know how many people have actually done that in recent times - but of course they are unlikely to admit to an illegal act.

I hadn't picked up that the OP was on a canal.
Link to Mainbrayce website, not that I would do anything illegal with 3 malta's to play with ! Mainbrayce – Alderney – Channel Islands – Marine Services – Chandlery – Fuel – Rigging – Sales » Our Services