67litres per hour at 22knots

[businessjett]

Hello,

I have a 2004 Searay 260da. It has the little 5.0-litre merc cruiser, single-engine.
At just over 4,000 rpm, it does about 20 knots. Based on the smart craft gauge it burns about 67 litres an hour.

Where I live in Australia it's open ocean, so not a flat lake or river.

1. Does that seem correct?

2. Also does trimming the engine leg help with field consumption etc.?

3. It only revs to about 4,200. Would that be correct too?


Thank you,
Byron

 

[Lazy Daze]

That converts to nearly 18gph and 23mph.

I see 4,400 RPM's on the tach. Is that at 23MPH?

Please clarify better - data needs to be accurate.

But, you should be able to do about 40MPH at WOT (roughly 4,800RPM). Lot's of things can cause this... just off the top of my head:

-- Not trimming properly
-- Bad fuel quality
-- Needs a tune up
-- Dirty/fouled bottom or running gear

Since you specifically asked about trimming... that may be your problem. Describe how you are currently trimming the engine.

 

[Scott215]

You can pick up five six miles an hour with the proper trim I would check the bottom of the boat if it's been sitting in the ocean

 

[businessjett]

That converts to nearly 18gph and 23mph.

I see 4,400 RPM's on the tach. Is that at 23MPH?

Please clarify better - data needs to be accurate.

But, you should be able to do about 40MPH at WOT (roughly 4,800RPM). Lot's of things can cause this... just off the top of my head:

-- Not trimming properly
-- Bad fuel quality
-- Needs a tune up
-- Dirty/fouled bottom or running gear

Since you specifically asked about trimming... that may be your problem. Describe how you are currently trimming the engine.

Thanks for making the time to write.

The bottom was just cleaned.
Engine just serviced

Yes that’s 23mph. Flat out. Will not rev more.

It’s possible I may have some dirt in the fuel.

I don’t understand trimming at all. I think if I push the top of both tabs it is suppose to help push the bow down ? Is that correct ?

That’s what I have been doing them leaving them. As I’m unsure how much I should then push the tabs at the bottom once on the plane.

If so how do I know their best position ?

Then with the leg . Should that stay all the way down also ?


Thank you.

 

[Scott215]

You need to trim up a little bit at a time. Back tabs off a little and tiny hits on the trim up and you will fell and see the boat speed up

 

[Creekwood]

The drive trim will impact your speed And bow height too. So there are a few things to adjust as you drive.

When you start up from a stop, Trim the outdrive all the way down (should be a switch on the throttle). Then apply full throttle to initially get up on plane. Once the boat pops up and starts to speed up, you can back the throttle off a bit. Then start to raise the drive trim to raise the bow. The optimum level is somewhat before the level that the drive starts to ventilate the prop. You will hear the prop start to ventilate and feel it too when the engine picks up speed, then trim down a bit from that. That should be close to the optimum setting for speed.

However in a head sea or rougher conditions you will need to trim the bow down using the drive leg, and slow down.

As for speed, I can’t help you other than to say that a 5.0l engine in a 26ft cruiser is not a fast boat. I would think that you would not get to 40mph wide open, but more like 35. But others with that actual boat will have real world numbers for you. The WOT RPM should be about 4800 though, so you may need to move to a lower pitch prop If you can rule out possible engine or fuel issues.

 

[Lazy Daze]

Thanks for making the time to write.

The bottom was just cleaned.
Engine just serviced

Yes that’s 23mph. Flat out. Will not rev more.

It’s possible I may have some dirt in the fuel.

I don’t understand trimming at all. I think if I push the top of both tabs it is suppose to help push the bow down ? Is that correct ?

That’s what I have been doing them leaving them. As I’m unsure how much I should then push the tabs at the bottom once on the plane.

If so how do I know their best position ?

Then with the leg . Should that stay all the way down also ?


Thank you.

Hearing that you don't know how to trim the boat is probably the best news since the fix is free. All planing boats behave roughly the same - they need trim for best performance.

For now, since you're so new to this, forget about the tabs - retract them all the way so they're not doing anything. Let's focus only on the drive trim.

To get on plane quickly, exactly this: Drive trimmed fully down, smoothly advance the throttle fully open. Once the bow starts coming back down you are now "on plane". Ease off the throttle to about 1/2 to 2/3 of fully open and start trimming the drive up. Hold the "up" button for two seconds and then see how the boat likes that. Give it another 1/2 or 1 second burst.

You're probably getting the idea, by now. Ver basically, the drive controls the bow. So to get on plan quickly, trim down. Once you're on plane, trim up to "free up" the hull a bit. If you want to go faster, keep trimming up. If you go too far, the prop will ventilate - back down a bit.

 

[b_arrington]

I'll kindly disagree with Dennis that a 260 DA with a 260 hp 5.0 will hit 40 mph.

I had a 2006 270 AJ which was very similar in size to the 260 DA. Mine had the the 300 hp 350 MAG Horizon 5.7 liter. That's larger than your 5.0 that produced 260 hp when new. The fastest I ever got in ideal conditions and a light load was 33 mph.

I would estimate that you're going to top out at around 28 mph, so let's use that as a basis. (If any owners with the 5.0 package disagree, I'll defer to their knowledge.)

I agree that your RPMs should be about 4800 so you're falling a little short there. That could account for the lower speed. A few things that can impact lower speeds and RPMs:
- Improper outdrive and trim tab trim settings, as discussed. Getting this right can add a few MPH.
- Too heavy a load. If you're full of fuel, water, gear and people, the boat can bog down and not hit speed.
- Fouled bottom (as discussed)
- Poor/old fuel.
- Fouled fuel injectors, assuming it's a MPI engine vs. carb engine. Mercury had issues with their cool fuel module where the inside was painted, and the paint flaked off into the fuel system. That lead to the injectors clogging and reduced performance. I had this happen, and lost a few MPH - could only get to like 24 mph.
- Too large a prop, if it was replaced.

I would assess your load and try out the trim procedures listed above and see how you do.

 

[Lazy Daze]

Brad, your experience is not the norm. Something else was amiss to cause such a low speed. But, the OP has the same "model" 260DA as I had (your 270AJ was based on the later, 2005-2009 260DA) and I also had 260HP. Every day of the week I could get 40MPH out of it... and it had no problems pulling me up skiing, either.

Now, even with your 270AJ/260DA... 33MPH is quite low - I've run many, many '05-'09 260DA and 40mph is no problem - even with the base engine.

I'm not discounting your experience - but there was some other variable at play there for you to have that low performance.

That said, I've never run a 270AJ, but I was always under the impression that the performance numbers were about the same as the 260DA that it's hull was based on? From memory, I think the general specs are about the same?

 

[b_arrington]

Brad, your experience is not the norm. Something else was amiss to cause such a low speed. But, the OP has the same "model" 260DA as I had (your 270AJ was based on the later, 2005-2009 260DA) and I also had 260HP. Every day of the week I could get 40MPH out of it... and it had no problems pulling me up skiing, either.

Now, even with your 270AJ/260DA... 33MPH is quite low - I've run many, many '05-'09 260DA and 40mph is no problem - even with the base engine.

I'm not discounting your experience - but there was some other variable at play there for you to have that low performance.

That said, I've never run a 270AJ, but I was always under the impression that the performance numbers were about the same as the 260DA that it's hull was based on? From memory, I think the general specs are about the same?

Dennis, as I said I'll defer to someone that owned one.

You're 100% right that my 2006 270 AJ was based on the 2005-2009 260DA hull. Both models used the same hull mold with the differences basically in how the decks were laid out; the AJ was more utilitarian. Therefore I agree that the performances should be very similar for those years. The AJ was a couple hundred pounds lighter due to less seating, but had about 20% more fuel capacity.

Anyway, I was wrong on on my boat's top speed. I found the pic where I got it to 36.2 mph so that's closer to what you experienced. I took a picture because it was the fastest I ever went I was surprised. This was after a bottom blasting job with a light load. It never got to 40 mph though.


My most efficient cruise speed was about 25-26 mph. The boat "felt" best at 28-29 mph.

In terms of fuel burn, IICR when everything was running right best cruise at I burned about 12-14 gph @34-3600 rpm. Preferred cruise at 28-29 mph at 3900 RPM burned about 16-17 gph. That 36.2 mph run @4800 rpm burned 22 gph.

So why didn't my boat go faster? I dunno. That's how it was from the start when I bought it new. Top speed was right in the 33 mph range for most of the time. That 36 mph speed was actually after 12 years of ownership and somehow it got faster. Shows what a smooth, fresh bottom job will do.

I had always assumed that this was the expected performance because the 350 MAG was the base engine (although I had the Horizon FWC option). The other options were the MX6.2 MPI @320 hp or the 496 Magnum @375 hp. For the 2007 model year Sea Ray made the 6.2 MPI the base engine. Boating Magazine did a review of a 270 AJ with the 6.2 engine and recorded a top speed of 38.6 mph, so that seemed to track to what I got. BTW, that article came out shortly before I bought my AJ so I had it in mind during my sea trials.
https://www.boatingmag.com/boats/sea-ray-270-amberjack/

I guess that's a long way of saying what I got from a a similar, but non-the-same model as the OP and what you owned. I'm sure there's a reason why your boat was so much faster.

 

[Stray Current]

Dennis, as I said I'll defer to someone that owned one.

You're 100% right that my 2006 270 AJ was based on the 2005-2009 260DA hull. Both models used the same hull mold with the differences basically in how the decks were laid out; the AJ was more utilitarian. Therefore I agree that the performances should be very similar for those years. The AJ was a couple hundred pounds lighter due to less seating, but had about 20% more fuel capacity.

Anyway, I was wrong on on my boat's top speed. I found the pic where I got it to 36.2 mph so that's closer to what you experienced. I took a picture because it was the fastest I ever went I was surprised. This was after a bottom blasting job with a light load. It never got to 40 mph though.
View attachment 150912

My most efficient cruise speed was about 25-26 mph. The boat "felt" best at 28-29 mph.

In terms of fuel burn, IICR when everything was running right best cruise at I burned about 12-14 gph @34-3600 rpm. Preferred cruise at 28-29 mph at 3900 RPM burned about 16-17 gph. That 36.2 mph run @4800 rpm burned 22 gph.

So why didn't my boat go faster? I dunno. That's how it was from the start when I bought it new. Top speed was right in the 33 mph range for most of the time. That 36 mph speed was actually after 12 years of ownership and somehow it got faster. Shows what a smooth, fresh bottom job will do.

I had always assumed that this was the expected performance because the 350 MAG was the base engine (although I had the Horizon FWC option). The other options were the MX6.2 MPI @320 hp or the 496 Magnum @375 hp. For the 2007 model year Sea Ray made the 6.2 MPI the base engine. Boating Magazine did a review of a 270 AJ with the 6.2 engine and recorded a top speed of 38.6 mph, so that seemed to track to what I got. BTW, that article came out shortly before I bought my AJ so I had it in mind during my sea trials.
https://www.boatingmag.com/boats/sea-ray-270-amberjack/

I guess that's a long way of saying what I got from a a similar, but non-the-same model as the OP and what you owned. I'm sure there's a reason why your boat was so much faster.

6.2 07 260 here, I see about the same. Much better after taking an inch out of the props

 

[Lazy Daze]

I dunno, guys I'm certainly not arguing with your experiences - they are what they are... and you guys even have video proof! All I can say is that I've run a whole bunch of '05-'09 260DA's. I have never hit less than 40MPH (only getting into the high 30's would definitely be something that would have stuck in my memory!). Usually I'm hanging right about 40/41. I remember taking a customer out on his boat - Rob D. - and was at 42mph (gps) - his boat had a 350MAG 300HP. I remember that one so well because I recall him being so surprised that it could do that well as he was only getting about 35 (or so he said).

Now, I am NOT magic - VERY far from it he just wasn't using the trim correctly... even though we all know that on this hull there isn't a whole lot of usable up trim to be used. But then, as a compromise, this hull planes out really, really well.



BUT... it just dawned on me that we're kinda going off script here since the OP has the older style 260DA

 

[Stray Current]

I dunno, guys I'm certainly not arguing with your experiences - they are what they are... and you guys even have video proof! All I can say is that I've run a whole bunch of '05-'09 260DA's. I have never hit less than 40MPH (only getting into the high 30's would definitely be something that would have stuck in my memory!). Usually I'm hanging right about 40/41. I remember taking a customer out on his boat - Rob D. - and was at 42mph (gps) - his boat had a 350MAG 300HP. I remember that one so well because I recall him being so surprised that it could do that well as he was only getting about 35 (or so he said).

Now, I am NOT magic - VERY far from it he just wasn't using the trim correctly... even though we all know that on this hull there isn't a whole lot of usable up trim to be used. But then, as a compromise, this hull planes out really, really well.

I’m thinking my numbers probably have something to do with a generator option, arch option, two section bimini, bottom paint, full water tank, full fuel tank, two passengers and a dog, and a decent amount of random crap stored in the cabin. I’m also usually fighting either wind or current to some extent. The super hot intake air temperature down here probably doesn’t help either and has it pulling a little timing

The best I’ve ever seen out of his hull lightly loaded was 38.5 and that was in December up north sucking 38° air on the way to the ramp to haul.

I’m going to run out on a limb here and say I’m trimming it properly.

Of course, that trim gauge sensor quit working almost immediately after it was replaced. I go by feel and sound.

 

[Lazy Daze]

I’m thinking my numbers probably have something to do with a generator option, arch option, two section bimini, bottom paint, full water tank, full fuel tank, two passengers and a dog, and a decent amount of random crap stored in the cabin. I’m also usually fighting either wind or current to some extent. The super hot intake air temperature down here probably doesn’t help either and has it pulling a little timing

The best I’ve ever seen out of his hull lightly loaded was 38.5 and that was in December up north sucking 38° air on the way to the ramp to haul.

I’m going to run out on a limb here and say I’m trimming it properly.

Of course, that trim gauge sensor quit working almost immediately after it was replaced. I go by feel and sound.

If you're doing it by feel and sound, then you're doing it right! Gauges? We don't need no stinkin' gauges!

You could very well be right with the weight you had causing the difference. Any 260DA (of the '05-'09 era) I've run has never had the genny - and that's easily worth a couple people in weight. And most, if not all, of the boats were loaded relatively light. My memory isn't good enough to recall fuel and water, but I know the boats weren't loaded down with gear.

 

[Jimmy Buoy]

Once on plane you might only want to only use one trim tab at a time to correct a normal list based on the boat's weight distribution. Both tabs can be used from an "off to on" plane transition IF you find that the boat is sluggish to get on plane. Then zero out both trim tabs once on plane, see how the boat is running, and if there is a list either to port or stb correct the list by using the one trim tab that will "push the high side down" to level the boat. Of course, this assumes that conditions are relatively calm.

This is in addition to the outdrive adjustments. Also, wind, wave activity, fuel and water levels, number of people and gear onboard and your speed will necessitate periodic adjustments to maintain your boats proper running attitude. It's very similar to flying a plane but rather two dimensional vs three.

Enjoy learning your particular boat. It will become 2nd nature quickly!

 

[blaster]

My question is how is the speed being measured?

 

[Stray Current]

My question is how is the speed being measured?

That’s a good point. If he is using the pitot he may actually be running several knots faster