I can't really give GPH from our 115 Mercury 4-stroke, but I have learned that it runs very economically at about 7knts and 18-20knts (about 4.200 revs)
Between about 7-13 you're just pushing water and burning fuel, 14 or so and you are planing nicely. Get the revs up to 5000+ and you burn a lot more fuel for the bit of extra speed (29knts is the maximum speed achieved)
Compared to the cost of marina fees at Sparkes, the difference in fuel economy between a petrol and a diesel isn't a major factor for our 70 odd hours a year.
Results 11 to 19 of 19
Thread: Merry fisher 645 or 655?
17-11-10, 07:07 #11
17-11-10, 08:48 #12
The layout is certainly ok, but I guess you haven't looked very hard at how the whole thing is glued together.
The 655 will top out at about 22 knots, but cruise economically (15 litres per hour) at about 16 knots.
It's a sea worthy little boat and cuts through a head sea slightly better than it's big sisters.
It does seem a little noisey at first, but you get used to the chatter of the engine and the sound levels don't increase to obtrusive even at high speeds. You can still have a conversation.
The 645 is the natural evolution to the Merry Fisher 625. Bit bigger and a better weekending layout. At 4000rpm epect to be using around 20litres per hour. I suspect this will be in the region of 17 or 18 knots. Increase to 4200 and you should be getting close to a 20 knot cruising speed and fuel consumption will be up to about 25 litres per hour.
In the grand scheme of things not a lot more than the diesel, when you realise you are going that bit further for the fuel burned.
The 645 will be that bit nippier and feel a little more like a sport boat when just out for a day of fun. The downside is that it will also feel a little bouncier in the water than the sure footed feeling of the inboard 655.
The 655, being semi displacement will be quite a wet boat and so make sure you have the second windscreen wiper, you'll need it. Being wet isn't bad, it means the boat is right in the water, which is where a semi displacement should be!
Oh, back on the subject of noise. You'll find it is quieter on the outboard boats outside in the cockpit area. The wheelhouse and cabin area on all of the smaller pilot house models acts like a giant sound box. Noise levels at planing speeds will be very comparable between the diesels and the outboatds.
The QS640WE with outboard feels very flimsey on the water. You can see bits waiting to fail. The boat really feels like it needs another 30 or 40HP as it labours itself onto the plane and is hard to hold there in any form of sea as it needs so much throttle being piled on to climb a wave.
I am a little prejudiced against the QS, but I've been on so many and seen the daft things leaking and breaking on nearly all of them, whereas on the range of boats from the Eau groups these failures are rare (not nonexistant, just rare).
In QS favour, IBS are excellent and will work hard to fix your boat when it does break.
Forgot to say, if you are trailering then an outboard boat will be ten times easier to launch and recover than a shaft drive boat.
Last edited by Nautibusiness; 17-11-10 at 10:29.CLIPPERTELEMED+
Global-Remote-Medical "Wherever You Dare"
17-11-10, 09:46 #13
We looked at the QS before we bought our MF625.
We felt the build quality of the MF and Beneteau was far superior to the QS. We also felt the MF was far more stable.
The 'eaus' also seem to have better resale values.'I will not be pushed, filed, stamped, indexed, briefed, debriefed or numbered! My life is my own!'
17-11-10, 11:44 #14
17-11-10, 12:54 #15
17-11-10, 13:00 #16New User
- Join Date
- Nov 2010
Thanks everyone for your thoughts and info.
I think i'll go with a merry fisher 645 package.
As a first boat it seems this would be a good all-rounder that i can't go too far wrong with.
Any 645 owners thoughts and veiws are welcomed.
17-11-10, 21:30 #17New User
Location : Gravesend, Kent
- Join Date
- Aug 2010
On speed and economy, mine climbs onto the plane at around 9-10 knots cruises most economically at around 3800 rpm 15 knots-4200 rpm 18knots and tops out at 5200 rpm and 28 knots, just like the brochure says (surprisingly). I reckon a similar sized MF will perform the same seeing as they share the same hull form.
I find QS s feel a bit cheap and flimsy by comparison.
18-11-10, 08:49 #18
They were originally aimed to be the "value for money" version. They did that job very very well. Cheap and cheerful, did what it said on the tin. Nothing wrong with the value for money end of the market so long as it remains value for money.
In the last 18 months the price gap has closed to such a point that the Eaus are really by far the more sensible choice and the resale values are much better too.
As a matter of interest, not really relevant, but as has been pointed out, various Merry Fisher and Beneteau models are almost exactly the same, save for a few basic, cosmetic changes. This because they share the same production line at Ostroda and previously in France.
Arvor are Brunswicks inboard diesel European angling boat offering and you may think that the Quicksilver (outboard boats) look remarkably similar. Well that is because they are the same boat changed to mount an outboard. The rear third to half if modified to suit.
Another, "just for the record" is that Quicksilver is Mercury Marines (Brunswick group) brand.
The other sister company, Mariner Marine, has Passport boats as their brand. Passport, again are exactly the same craft just with a marginally different gel coat colour and decals. For some reason, Passport have never taken off in the UK where as Quicksilver and Arvor have both been a huge success. Maybe it's down to marketing?
Global-Remote-Medical "Wherever You Dare"
25-11-10, 01:24 #19
I have a Beneteau Antares 6 which is identical to the MF 655 apart from a few cosmetic changes. They both come off the same production line. Mine is the Yanmar powered one but unless my GPS is telling lies it will not do 22 Knots as stated. It won't even reach 20 knots in fresh water at 3400 rpm, clean bottom, and factory supplied propellor. The maximum revs according to the handbook should be 3250 which makes me wonder why it will rev higher? May be worth an enquiry at the 50 hour service. I find the boat very economical and there is plenty room for the size of the boat(now that the cockpit canopy has been fitted). I find the seperate head a godsend as do any passengers I have had aboard. This may be worth thinking about as the 645 does not have a seperate head compartment. Good luck with your decision and I can only say that I am very happy with mine. You will need a big truck to pull one mind as it is almost 3 tons with trailer and about 12 ft high on the road but launches/recovers fine on a proper slipway although I wouldn't like to try and beach launch it. If trailering is your choice I would go for an outboard model unless you have a big 4WD. Hope this helps.