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Old 30 January 2008, 13:14   #1
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60 hp engines two stroke or four (running costs?)

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?
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Old 30 January 2008, 15:53   #2
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Originally Posted by two stroke mick View Post
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?
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Old 30 January 2008, 16:06   #3
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I would say it depends on usage but in my opinion, 2 stroke.
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Old 31 January 2008, 04:20   #4
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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.
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Old 31 January 2008, 04:42   #5
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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?
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Old 31 January 2008, 05:02   #6
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Originally Posted by two stroke mick View Post
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
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Old 31 January 2008, 05:18   #7
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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.
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Old 31 January 2008, 05:21   #8
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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.
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Old 31 January 2008, 11:54   #9
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Your thought this engine on a Valiant DR 490



http://www.boatsandoutboards.co.uk/view/BHM348
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Old 31 January 2008, 15:38   #10
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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
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