2 stroke vs 4 stroke

jetski · 09 May 2009, 06:45

On my quest for knowledge again, sorry , On engines fuel injected 80 hp > 150 hp are 2 stroke or 4 strokes most favoured ?

Leapy · 09 May 2009, 06:49

Quote:

Originally Posted by jetski

On my quest for knowledge again, sorry , On engines fuel injected 80 hp > 150 hp are 2 stroke or 4 strokes most favoured ?

Oh boy. Here we go...

Nos4r2 · 09 May 2009, 07:53

Quote:

Originally Posted by jetski

On my quest for knowledge again, sorry , On engines fuel injected 80 hp > 150 hp are 2 stroke or 4 strokes most favoured ?

No-one can tell you that without a long argument. Try both.Make your own mind up.
Generally in the sub 115hp bracket there's a significant power/weight advantage in having a 2 stroke.

Depends what you prefer-loads of grunt plus some noise (it varies) or a bit less out of the hole, bit more weight but near as dammit silent.

neilda · 09 May 2009, 08:11

Would a four stroke be more reliable?

I speak with the benefit of profound ignorance. However garden machinery and motorcycles seem to be more reliable machines when they're 4.

Probably different with boats.

Nos4r2 · 09 May 2009, 08:32

Not really...

It's a hard question-nothing is 100% reliable, and most failures/problems on leisure use engines are down to salt water exposure,long periods of inactivity and poor maintenance. 2 strokes do wear out faster than 4 strokes, but when a leisure use 2 stroke can last 20+ years before it's physically worn out, the comparison is irrelevant as by that time corrosion damage or neglect will be causing far more problems.

Marine 2 strokes certainly don't suffer problems in the same scales as 2 stroke bike engines do-they rev far lower and are far heavier duty build quality.If they broke down a lot they simply wouldn't sell.

jetski · 09 May 2009, 08:34

From what limited information I have, hence the thread

2 strokes are lighter, modern ones have similar fuel consumption and fuel injection is preferred to Carbs.

Iwas hoping to have this either confirmed or ny theroy blown out of the water we will see

Nos4r2 · 09 May 2009, 08:45

Quote:

Originally Posted by jetski

From what limited information I have, hence the thread

2 strokes are lighter, modern ones have similar fuel consumption and fuel injection is preferred to Carbs.

Iwas hoping to have this either confirmed or ny theroy blown out of the water we will see

That's about the size of it-apart from the noise issue. 4 strokes are quieter-despite Evinrude's claims about Etecs-and 2 strokes have a lot more grunt from a standing start.
Personally, I rather like the noise of an engine behind me.

You do have to look at the weights in comparison though. Due to manufacturers using the same engine blocks to produce different HP, some 2 strokes don't have the weight advantage. Optimax 90s for example are pretty much the same weight as 90 4 strokes.

It's the same as anything else. Everything has an exception and it's always worth looking twice at everything.

Markyboyo · 09 May 2009, 09:44

Just as Nos says, try them and make your decision. It's what is better for YOU that matters!

My etec suits me and my boat down to the ground and I like the face that it is noisier than a four stroke! You wouldn't want a sports car that sounds like a micra would you...

chewy · 09 May 2009, 10:01

Do you need to consider the 4 stroke paying for itself or not. The fact 4 strokes are cheaper to run attracts some people.

Nos4r2 · 09 May 2009, 10:32

Quote:

Originally Posted by chewy

Do you need to consider the 4 stroke paying for itself or not. The fact 4 strokes are cheaper to run attracts some people.

Optis, Etecs etc don't have any real significant cost increase any more to run than 4 strokes once you add on the extra servicing costs of a 4 stroke.

codprawn · 09 May 2009, 16:03

When you get up to big engines over 200hp the weight savings are a lot. A Mercury Opti 225 weighs 229kgs - the Verado 225 weighs 288kgs.

As far as I can see it the main advantage of a 4 stroke is that it is so quiet BUT over about 20kts there is more noise from the wind and waves anyway - you only hear the engine in the harbour!!!

I would go for a 2 stroke most of the time.

just look at an old 90hp 2 stroke against a new 90 4 stroke. The 4 stroke looks huge in comparison. My Suzuki 225 looks tiny compared to a modern 225 4 stroke.

Leapy · 09 May 2009, 16:14

jambo · 09 May 2009, 16:27

Quote:

Originally Posted by Leapy

Are you desperate to underline a point

;cheers:
J

Leapy · 09 May 2009, 16:29

Quote:

Originally Posted by jambo

Are you desperate to underline a point

;cheers:
J

It's great debate...as it was last time...and the time before. It's one of life's unanswerables that brings out the best and worst of opinion

jambo · 09 May 2009, 16:40

Quote:

Originally Posted by Leapy

It's great debate...as it was last time...and the time before. It's one of life's unanswerables that brings out the best and worst of opinion

I agree wholeheartedly with you, I just wondered if you had another burning point to make. I myself am a true 2 st man surrounded by various variations of 4 st and overall there is not over the piece much between them apart from personal choice and what you want from it. Codders point is a good one re the noise level.

J

JSP · 09 May 2009, 16:46

I got told the saving on fuel with 4 stroke engine's isn't that much when cruising fast or at WOT?

Have to say, at least with my 2 stroke I've (with the guiding hand of RIBnet) been able to service it myself with regards to, gear oil etc. Would it have been the same case with a newer 4 stroke?

Leapy · 09 May 2009, 17:28

Quote:

Originally Posted by jambo

I just wondered if you had another burning point to make

Nah...just enjoy the theatre

BogMonster · 10 May 2009, 13:30

Quote:

Originally Posted by Nos4r2

Personally, I rather like the noise of an engine behind me.

Me too - after all if you are paying all that money in fuel you might as well get the most out of it

I love the noise of the V4 when you open the taps

JSP · 11 May 2009, 10:14

Quote:

Originally Posted by BogMonster

Me too - after all if you are paying all that money in fuel you might as well get the most out of it

I love the noise of the V4 when you open the taps

Have to agree but find my yam a little quiet compared to other similar sized 2 strokes. It grunts but not as loud as most.

jambo · 11 May 2009, 11:59

Agree with you both I love to hear my lovely V6 mariner 2st purring away behind me.

J