CONTINUOUSWAVE

I [may buy] a 2005 240 OUTRAGE with a single Mercury 225-HP two-stroke engine. Most 240 OUTRAGE boats seem to have either twin 135-HP engine or twin 150-HP engines.

Will a 2005 240 OUTRAGE with a single Mercury 225-HP two-stroke engine boat be under-powered?

What performance can I expect?

Will a 2005 240 OUTRAGE with a single Mercury 225-HP two-stroke engine get on plane easily?

Will a 2005 240 OUTRAGE with a single Mercury 225-HP two-stroke engine cruise at 30-MPH without the motor screaming?

The engine on a 2005 Boston Whaler boat should have been a Mercury OptiMax 225. If it is just a "two-stroke" then someone has changed the original engine. I presume the boat has an Optimax 225.

Boston Whaler publishes extensive information about the performance of their boats when they have pre-installed and pre-rigged the engine. You should consult the published performance data from Boston Whaler to get accurate information on performance. You can find an archived copy of their performance data at

http://web.archive.org/web/200611090436 ... ageEng.pdf

As you will see from the Boston Whaler factory test data, the boat speed should exceed 40-MPH.

To reach 30-MPH boat speed, the engine speed required with the single OptiMax 225 was about 4,400-RPM.

As for engine noise, the OptiMax is a noisy engine at idle speeds compared to other engines. For example, it is 64-times louder than a VERADO six-cylinder at idle. At engine speeds of 4,400-RPM the difference in sound level between engines is generally less.

I am certain that at 4,400-RPM you will be very aware of the engine noise from the Mercury OptiMax 225-HP, but so would you be with just about any 225-HP engine or any twin engines of lower individual horsepower.

You will also find some interesting comments about the 240 OUTRAGE with a single engine in an earlier discussion.

I see the decision matrix like this:

--do you want a 240 OUTRAGE?

--do you want a boat with twin engines?

--can you be satisfied with a single engine?

--can you be satisfied with a Mercury OptiMax?

I don't think twin engines are really necessary any more on 24-foot boats because there are plenty of 250-HP single engines or even 300-HP single engines that will give equivalent boat speeds. The argument about twin 150-HP engines being a thing of the past was discussed some time ago. Let me reprise some of my comments that are applicable here:

Are installation of twin 150-HP motors a thing of the past?

With larger horsepower outboard motors available, will boats with ratings for 300-HP maximum be more likely to install a large single engine rather than twin 150-HP motors? There seems to be some incentive to a move in this direction on the basis of weight, cost, and performance.

The cost of twin engines is also significantly higher than a single engine installation. Usually the price of a higher horsepower motor is less than the price of a pair of motors of half horsepower. In addition to the double engine costs, there are double expenses for controls, instrumentation, propellers, and installation.

Performance should be about on par with either single or twin installations. Depending on the particular hull and motors, twins sometimes seem to be able to approach the same fuel economy as a single, but generally the edge goes to a single motor. Twin propellers offer more blade area and often produce better handling, but improvements to propeller design may make the differences not as great as in the past, giving a single nearly equal standing.

Boston Whaler seems to have cast its vote: a big single is preferred over twins. They have several newer boat designs where the transom is built only for a single engine. In the past, boats in the 300-HP size range, like the CONQUEST 235 for example, might have had an option for twin power; now it is only available as a single engine boat.

Perhaps the greatest reason for twin engines is the redundancy. However, with modern engines becoming more reliable, perhaps the notion of needing twin engines for a hull with a 300-HP rating is becoming old thinking. It seems like it.

How I gauge "underpoweredness" is what RPM does it take to cruise at 30 MPH. For a 2-stroke with a WOT limit of about 5500 and 6000 RPM, cruise RPM should be no more than 4000 RPM otherwise the boat is underpowered. Under that criteria, the 240 Outrage is underpowered. In the performance reports, the 225 has the worst fuel economy at cruise of the bunch. Another sign of underpoweredness.