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Old 01 August 2016, 01:23   #1
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Ideal Cruising RPM's

I know it's a case of how long is a piece of string....but that said, what rpms do you guys normally cruise at.

My outboard is a 2012 150 Yamaha Fourstroke.

I cruise at 4,000 rpms, but would truthfully prefer to be at around 4,500, but it sounds like I am thrashing it and I don't want to tear it up. It does sound much sweeter at 4k, but hauls ass better at 4.5.

Thoughts?
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Old 01 August 2016, 02:22   #2
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A short storey long!! We decided passengers don't chat and stop enjoying the cruising experience above 25knots, between wind, waves thumping etc. 20knots is a little slow, so for us its 23/23 knts at 4250 (depending on prop) Also when you say best cruising speed do you mean best for range? I would have thought 4250 is probably best range revs also (approx).nik
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Old 01 August 2016, 03:05   #3
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The first thing you need to determine is whether you are correctly propped. Can you reach your WOT range with your normal load? If so, it's a case of what's comfortable/economical for your rig. I have a Suzuki DF140a lean burn. The most economical rev range is around 4500 which just happens to be around 25kn. I am propped spot on at 6000rpm WOT. If you are correctly propped you won't be stressing your engine at 4500, assuming your engine's WOT is around the 5500-6000 mark


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Old 01 August 2016, 03:15   #4
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My yam 4 stroke has a max rpm of 6300, I have no problems running at 4700 for long periods to get offshore. An average day on the water is normally over 100km.

According to Yamaha Au these engines are designed to run at even higher rpm for long periods at a time without causing any problems. Why not ask a reputable Yamaha dealer or Yamaha UK.


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Old 01 August 2016, 04:15   #5
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Why not ask a reputable Yamaha dealer or Yamaha UK.
When there's such a plethora of informed members on here
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Old 01 August 2016, 04:33   #6
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Your sig says it is a merc 150?

If it is a yam then Davie if the one to ask on here for an informed answer.
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Old 01 August 2016, 04:52   #7
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It also depends on your boat as to what power is needed to keep you on the plane at that "relaxed sweet spot". As you say yourself, you'll "feel" when it's right or stressed.

The same 150hp engine will vary in terms of the sweet spot from boat to boat I'd imagine.

We cruise at 3800-4200 with a 2 stroke 175 optimax on a 6.3 rib, depending on load. My mate has the same engine on a bayliner type cuddy 6.5m and needs to sit at about 4600-4800 to "feel" relaxed, as there's much more weight.

And all that varies on the prop you have on, as others have said.
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Old 01 August 2016, 05:19   #8
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Your sig says it is a merc 150?

If it is a yam then Davie if the one to ask on here for an informed answer.
Haha, it is a merc. I don't know why I said Yamaha, perhaps it's a subliminal desire to own a yammie or a sign that early morning posting needs to be better monitored.
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Old 01 August 2016, 05:35   #9
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The first thing you need to determine is whether you are correctly propped. Can you reach your WOT range with your normal load?
^^^This.
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Old 01 August 2016, 08:53   #10
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I will get out on the boat next week and see what wot is, then repost.
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