engine size

[nik]

Hello all,

Can anyone tell me how well a 5.3m ocean pro (300Kg) would go with a 50hp 4 stroke o/b, a suzuki maybe.

Thanks, Nick.

[Rogue Wave]

that would be fine but not so fast whats the max power for the transom is it around 90

[nik]

I have been told around 27 knots. Does that sound on the mark?
Nick.

[Rogue Wave]

yep maybe a littel less it will definitely plane the extra Hp just gives you more speed and more snappy acceleration but the fifty will do it!

[nik]

Thanks

[xpertski]

hey there, the 50 hp should do the job, but it depepnds how many ppl would be on the rib usually, if more than 3 i would suggest going for larger hp, as the ocean pro can take pretty large engines, i would have thought a 70hp suzuki would fit the bill, and is also the same weight/size as the 60hp! i have the 6.3m ocean pro, bought last year, with a 140hp it is balanced, and my previous boat was a 4.7m zodiac pro 3, with 50 hp, it had a shallower vee than the humber, and the 50 made it a nippy boat, but although its lighter than the 5.3m ocean pro, it was working very hard at 30 knots/ish, with 4ppl on board, would have suited a 60hp i think, so with this in mind, it may be worth considering higher hp! itll be interesting to see what you decide, best of luck, jonathan

[nik]

Its just that there is a big price hike from 50hp to 60hp

[Rogue Wave]

Nik, in my opinion it's good to max the power on a rib, however when you consider the extra expense in buying ans running a bogger engine is too much go for the smaller one.

Just get out on the water and have a good time,

personally I'd stick a 2stroke 70 on in preference to any 4 stroke but theres an awful lot of 4 stroke owners would disagree!.

Are you buying the engine new!

[nik]

Up to now I have not paid too much attention to outboards, favouring the idea of a diesel.

But now I have scaled back my ambitions, which means going for an outboard.

The sum total of my knowledge is:
Fourstroke good but heavy
Old twostroke expensive to run but responsive
New twostroke much better than old, but is it better than four stroke.

Also, are modern twostrokes cheaper than fourstrokes on an equal Hp rating?

Nick

[Downhilldai]

It depends on how much you'll use it and how concerned you are with running costs v performance. I'd agree with Rogue Wave and go for a two stroke 70 ish (maybe second hand - cheap?) to start with and see how you get on. It would be cheaper than a 50 4-stroke and give a lot more fun, especially if you have a crowd on board, which is likely in a 5m+ RIB on a nice summer's day. There's nothing worse than an under-powered boat, even if it is cheap to run. I'd try to get a test run on a similar size/weight boat to what you have in mind, if you can find one with a 50 hp, and see what you think of it.
Good luck.

[Mike B]

Agree with the above - 2 stroke and try and aim for a bit more Hp.

My 55hp on a 5.2m (prob shallower vee than humber) is great with 2 but still only 34 kts WOT.

With 4 people it starts to get a bit sluggish and with more it can seem like an age to get out of the hole and on the plane.

I bought it secondhand with the 55 on it but would like to put an 80 on which is the max for my hull.

[xpertski]

fourstrokes are not necessarily heavy, the suzukis for example seem to do quite good on weight, but the hondas struggling to keep the weight down! i admit there is a big difference in prices, however one consideration may be to buy engine separately, for example see what offers you can get, i know a reasonably priced seller in the midlands, the company is T L Harvey, type that into google and youll find their website, contact them and ask for john harvey. they do some very good deals on engines and packages for that matter! as basically the bigger hp within the reccommended range the better, but its also hard to stay within a budget......always haha! say hello from me if you do call john, let me know how it goes! jonathan