What to buy now - 2 Stroke or 4 Stroke

Rib Master · 21 September 2007, 08:08

OK, so you are about to buy a new RIB

The question is what outboard do you go for?
New 2 Stroke or a 4 Stroke?

What is the price differential?
What are the running costs?
What is good for all round use including skiing?

I have been to the boat show and different suppliers are promoting the benefits of both 2 and 4 stroke.. So what should one choose?

Specifically I am after an 8mtr rib, so what engine and HP to go for?

any ideas?

ed2 · 21 September 2007, 08:32

We have just bought ourselves a 5.5m RIB with a Suzuki DF70 Four Stroke engine. It seems very reliable and she runs really well.

Now, this engine is only a year old and has only just had its 20 hour service, and our two stroke engines have been quite old.

However, based on our experience, the new 4 stroke is a hell of a lot more fuel efficient. We managed to have the engine in idol tick over for about 3 hours and do around 14 miles flat out on only £6 of fuel. I knoe ablw your setup will be completely different no doubt (bigger engine, bigger RIB), and I am sure that somebody will be able to help you more specifically.

Cheers,

Ed

Darren Bruce · 21 September 2007, 09:06

Hi,

I am in the same boat, so to speak. I will be purchasing a 6.5M as a safety boat for the company I work for and I did a similar thing at the Southampton Boat show of walking around asking peoples opinion. Some say 2 stroke as there are less moving parts to go wrong, but personnally I think 4 stroke because they are smoother and quieter. There are as many people prefering Honda than people prefering Mercury and although Mercury have been around for a long time I do like the Japanese for their motoring quality. Honda carry 5yr warranty as oppose to the standard 2 or 3yr. In the high power range (150-275HP) The Merc 275 Super charged was by far the quietest even at 2000rpm and the Merc 150 provided excellent performance on a 6.5M but I think the 4 blade prop mades a difference. so, who ever gives you the better deal... I don't think you would be disappointed with either.

I would like to know what you decide in the end...

:-)

Lostboy · 21 September 2007, 10:09

I am a bit two-stroke fan as my Evinrude has been quiet, economical (10l/hour average for the past two seasons), is lighter than a four stroke (important on a light boat!) and is reliable. Given that this model is now superseded by the quieter, allegedly more economical and even simpler (and therefore perhaps even more reliable) ETEC then I don't see the point of going down the heavy, expensive-service-cost route of a 4-stroke.

Jelly · 21 September 2007, 10:51

Putting it crudely it depends what you want your boat to do !
Safety / stand-by work where you are pottering around a lot then I would look at 4 strokes
If you want to play with water toys etc and need the hull shot then 2 strokes win every time.
If you are some where in between on your requirements thats were it gets a bit gray
James

Ian M · 21 September 2007, 13:20

My cars have always been 4 strokes, my bikes have usually been 4 strokes (except the racing ones

), but it is 2 stroke every time for my outboards. Forget the arguments about fuel economy, there is nothing to choose in this area between a modern 2 stroke and 4 stroke. My reasons are the lighter weight of a 2 stroke, lower servicing costs, and they usually sound better

( and coming from someone like me who can remember the glorious sounds of various 4 stroke racing machines from the late 60's and 70's that is saying something).

Rib Master · 21 September 2007, 14:00

Thanks for the feedback.

I think I am pretty much decided on an Optimax 225.

The Boatshow was an interesting yet confusing time.

I nearly went Suzi 250 with vvt but then the price is a bit painful...

Based on Optimax tried and tested engines and price at the moment, I don't think I can go wrong with this choice.

Currently I am at £10k all fitted to a new 8.3Mtr but that may be subsidised by the rib manufacturer..

Lostboy · 21 September 2007, 14:18

Right decision regarding the number of strokes, wrong engine , IMHO!

iainmartins · 21 September 2007, 18:38

don't worry the optimax is a good engine and it is well proven, and the spark plugs last more than 50hrs like they do on a lot of e-tec's. Were problems in the past with powerheads breaking, but I know loads of people with them that think they are the best.

Roy Smith · 21 September 2007, 21:24

I am a four stroke fan but i would change if some one could tell me what i would gain by going 2 stroke, have you looked at Yamaha.
If you are looking at powering a 8 mt rib you need a good engine.
and in the real world we did Northney Marina to St Peters Port Guernsey
112 miles average speed 38 kt fuel used 177 lts
I think the Verado and the Suzuki are just as good just depends what you are happy with. there is also the resale value to take into account
I can only speak from my experience.

Hugh Jardon · 22 September 2007, 09:10

i went opti as well and it was a choice between price, power, weight, looks, warranty, resale, other unproven units at the time.

i went opti and very very pleased with it, lots of oompf and good economy and a great noise.

if you think you are going to be as quiet at lower speeds as a 4 stroke then forget it but at cruising speeds and higher speeds it is absolutely fine. Some people complain they are noisey but perhaps they did not get out there and test ride some and do their homework properly.

try to test ride a boat with one on the back and if you like the noise then you are all set.

Mollers · 22 September 2007, 10:40

Cost of purchase plays a large part in the decision process. You can put up with a bit of noise etc. for a good few grand saved. I'll probably go for an Etec next time as it's pretty good in most depts and comes in somewhere between an Opti and a 4st regarding noise.

Chris · 22 September 2007, 11:18

I am biased as I own one but I really like the Etec I have on the back of my boat and a freind who has an Optimax said he would not go for one again purely because it is so noisy especially at cruising speeds. Its not ideal if your carrying passengers and can be quiet tiring.

The Etec at idle is very quiet in fact you can hardly hear it and although not as quiet as a four stroke under way its not far off.

I was in Cardiff Lock with another Rib that had a pair of Large Optis on the back and it sounded like a pair of tractors running in there !

Chris

Quote:

Originally Posted by Rib Master

Thanks for the feedback.

I think I am pretty much decided on an Optimax 225.

The Boatshow was an interesting yet confusing time.

I nearly went Suzi 250 with vvt but then the price is a bit painful...

Based on Optimax tried and tested engines and price at the moment, I don't think I can go wrong with this choice.

Currently I am at £10k all fitted to a new 8.3Mtr but that may be subsidised by the rib manufacturer..

Aidan · 22 September 2007, 22:00

I dont think anyone has has said it yet, but if you are skiing etc behind boat, the smell of a 2 stroke in you lungs having just skied and looking for O2 can be a put off.
However the 2 stroke has more grunt to get boat out of water.
While you are at it, using Hydro planes off engine gets the stern out faster so the engine can use its grunt to pull out Skier.

I had a marlin 16 with SUzi 70 behind and found it needing much more power.
It would not have pulled a skier out of the water on mono.

My guess is to try one first for skiing mono and see!