60 hp engines two stroke or four (running costs?)

two stroke mick · 30 January 2008, 18:14

Your thoughts on a 60 hp 2 stroke vs a modern 60hp 4 stroke. Is the saving in fuel enough to justify the extra cost on such a small engine?

mdt · 30 January 2008, 20:53

Quote:

Originally Posted by two stroke mick

Your thoughts on a 60 hp 2 stroke vs a modern 60hp 4 stroke. Is the saving in fuel enough to justify the extra cost on such a small engine?

is it a new DI 2 stroke?
are you going to use the boat lots?
how are you goiong to use it ...tow toys etc?
are you looking to sell it any time soon?

Jizm · 30 January 2008, 21:06

I would say it depends on usage but in my opinion, 2 stroke.

danwells · 31 January 2008, 09:20

Quote:

Originally Posted by Jizm

I would say it depends on usage but in my opinion, 2 stroke.

yep defonatly 2 stroke for me. thats only becouse i run a two stroke on my boat aswell.

two stroke mick · 31 January 2008, 09:42

My thoughts are a 60 hp old style two stroke will use at WOT a two stroke will use circa 6 gal/hour a four stoke will use a similar amount.
At crusing speed I would expect a two stroke to use circa 4.5 gals/house (20 l/hr) a 35 % saving on this figure by a four stroke would be circa 7 l/hr.
The differance in cost between a new 4 stroke and a new 2 stroke is substantial and I think that it would take a very long time to recover my costs. The servicing costs would also need to be a factor in this calculations. I under stand that 4 strokes are more expensive that 2 to service. I would be intending to use the engine on a 4.9m valiant rib.

Please comment on this observations, are my figures for this calculation close to the the actual experances for this size of a rig?

Pete7 · 31 January 2008, 10:02

Quote:

Originally Posted by two stroke mick

Please comment on this observations, are my figures for this calculation close to the the actual experances for this size of a rig?

Some good news they are a bit high actually

. (Rough formula is: 1 US Gallon per 10 hp per hour)

60hp Merc 2 stroke on a 5.2m Opsrey Sparrowhawk. Flak speed (5000 revs) 5 gallons an hour.

70 Hp Evinrude 2 stroke on Ribtec 535 at flak speed (5000 revs) 4 gallons an hour.

The Ex RNLI Evinrude swung a bigger prop than the merc and seemed to grip much better. Great little engine and as already mentioned I doubt you would save much by going 4 stroke. Honda et al will probably claim 30% savings at tickover, but if your only using 2lph at tickover thats hardly worth considering, and there has been some scary figures published for bigger 4 strokes running at speed.

Pete

9D280 · 31 January 2008, 10:18

I guess if you're talking about use mostly at the top end of the tacho scale you won't see much of a difference in consumption , as I've said before - to get 60 Hp at the prop you need to burn a certian amount of fuel...... If however you are for example going to do a lot of pootling about for fishing or dinghy rescue or whatever reason and spend a lot of time at idle speeds, then a 4- stroke will drink less, and do it more quietly as well. But as you say, even at today's prices that's a lot of running to recoup the difference!

Also to take into consideration if you're hanging it on a secondhand hull, check the transom loadings - Older RIBS will be rated for the lighter 2- strokes. Mine is a '79 vintage, and rated to 60Hp. I couldn't hang a 60Hp 4-stroke on it 'coz of the weight.

Pablo · 31 January 2008, 10:21

If you're talking about buying new then your choice of 2 strokes are limited. Optimax, Etec, Tohatsu or Selva (there may be others). Tohatsu and Selva are doing interesting bargains in France at the moment, maybe other there too ? Otherwise I have the impression, but I don't know much and i'm only repeating what i've heard here, that the prices are pretty much the same.

The fuel consumption is pretty much the same now with the new 2 strokes.

I've just bought a second hand old style 60 hp Yamaha autolub 2 stroke which comes to a damed site cheaper that a new one. 1500€ rigging and 1 year garanty included. I haven't had it out much yet so I can't give you much info on fuel.

Alot depends on what you want to use it for. An old style 2 stroke isn't suited to trolling at 2 knotts.

two stroke mick · 31 January 2008, 16:54

Your thought this engine on a Valiant DR 490

http://www.boatsandoutboards.co.uk/view/BHM348

ian parkes · 31 January 2008, 20:38

I had a suzuki df 70 on my 4.9 valiant , it averaged 1/2 litre a mile used fairly hard ,
i did once or twice top it up after anhours cruising and it used between 10 and 15 litres so approx 2.5 gall per hr on average .

i can't comment on the economy of that evinrude but i would look at the wieght if its around the same wieght as the etecs the 490 will fly as the tubes will get clear of the water , the df 70 at approx 180 kg I felt was a little on the heavy side for the boat ,the 75 etec i tried on a demmo boat had lots more punch than the suzuki

Go steady though if youe are alone it could get a bit twitchy

Pete7 · 31 January 2008, 21:00

Quote:

Originally Posted by two stroke mick

Your thought this engine on a Valiant DR 490
http://www.boatsandoutboards.co.uk/view/BHM348

Same price as I paid for my Evinrude 70 in 2000 (engine was about 5 years old). I am not sure quite what the RNLI do to marinise ther engines but they put back a lot of the original parts when they de-commision them, hence the fly wheel and carbs looked brand new. The rest of the engine was spotless and a quick polish was all that was needed. The red letters give her age but simply peel off.

Is it worth £2.5k in todays market?, well Bill Highman has a reputation of charging top wack, but they are good engines, the design as changed little in 20 years becuase they got it right in the first place. Be aware the are 50:1 mix engines. However for that money your in 4 stroke 50 - 60 hp price range. There is one on boats and outboards, but looks like Dan our favourite Norfolk dealer is selling it so your taking a risk.

How about this one:

http://www.boatsandoutboards.co.uk/view/OAB438

Slight older but a grand cheaper and a boit closer to you:

http://www.boatsandoutboards.co.uk/view/F168451

Pete

two stroke mick · 31 January 2008, 21:15

Will the fact that the petrol and oil is pre mixedmake the engine smoker/smeller than a oil injected outboard?

Pete7 · 31 January 2008, 21:36

Quote:

Originally Posted by two stroke mick

Will the fact that the petrol and oil is pre mixedmake the engine smoker/smeller than a oil injected outboard?

Not that you would notice compared to another 2 stroke but is noticeable over a 4 stroke.

Seen this advert? you could ring him up and ask about the combination.

http://www.boatsandoutboards.co.uk/view/F170185

two stroke mick · 01 February 2008, 08:56

Hi pete 7

I just sent an e-mail to that ad in B&O to ask can I call him about the rig you spotted on the net. Well done thanks for the good idea

9D280 · 01 February 2008, 14:53

Quote:

Originally Posted by two stroke mick

Will the fact that the petrol and oil is pre mixedmake the engine smoker/smeller than a oil injected outboard?

Probably not IF you mix it right and don't spend too long wandering around at idle speed....... I know people who would "add a bit extra oil just to make sure" and of coures the tank would never fully empty, and the next fill got a liitle more extra oil.....

Autolube / Automix / substiture you favoutrite brand's name for it only really comes into its own if you are running at low RPM a lot, otherwise it's more weight and more to go wrong!

My old Oil injected Suz averaged about 53:1 when I compared the fuel to oil I had poured in over the year- and that was with a week playing rescue boat in a year of cruising.