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Thread: Good information for potential Yamaha user's

  1. #1
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    Default Good information for potential Yamaha user's

    Four-Stroke Outboard Engine Test: Twin Yamaha 115s vs. a Single Yamaha 225
    In this outboard engine shoot-out, we pit twin Yamaha four-strokes (115 hp each) against a single Yamaha 225-hp four-stroke. The motors were tested on 23-foot recreational fishing vessel from Angler Boats.
    In Powerboat Reports’ constant quest to find more fuel-efficient propulsion packages, we decided to compare two identical boats (Angler 23 VBX center consoles)—one powered with a single four-stroke outboard (Yamaha F225), and the other with twin four-stroke engines (Yamaha F115s). PBR testers recorded fuel flow, noise levels, speed, and calculated mileage and range figures. The boat with one engine kicked butt in every category, with the greatest advantage coming at trolling speeds (7 mph). The boat with the F225 also costs less than the boat with the twins.
    We want to help you buy the right propulsion package for your boat. Many boat manufacturers offer both single and twin-engine applications. With the increased reliability of today’s four-strokes, the appeal of a second engine as a backup has lessened to a great extent. Fact is, these engines are more dependable than ever. So why spend money on two, when one could potentially do the job?



    Our goal was to find out whether a single 225-hp four stroke could indeed do the job in the areas of speed, fuel economy, and engine-noise levels when matched against a pair of 115-hp four strokes. Sure, the twin-engine setup has a 5 horsepower advantage, but as we’ve reported in the past, horsepower ratings are not based on an exact science. In powerplants this big, with hundreds of horses at work, five horses are negligible

    A single Yamaha F225 and twin Yamaha F115s were mounted on identical Angler 230 VBX center console fishing boats. With each boat, PBR testers recorded fuel flow, speed, and noise levels at increments of 500 rpm. We also took fuel and noise readings at trolling and cruising speeds. The charts on page 9 show fuel-burn rates, mileage, and range at 7 mph, 23 mph, and 29 mph. PBR conducts this speed

    The engines were tested on identical Angler 230 VBX center consoles. Both had half a tank of fuel and two people on board.

    vs. speed evaluation when comparing engines of dissimilar technologies (two-stroke vs. four-stroke) or unequal horsepower. Testing took place on Key Biscayne Bay in Miami. To account for wind and current, testers took fuel flow, speed, and noise levels in two directions and then averaged the figures.

    What We Found

    We measured significant differences in noise levels between the two engine options, sometimes as high as 10 decibels. At trolling speeds and power settings, the variations were minor (not noticeable to the ear). But at higher speeds, the twin-engine package’s noise levels were an average of 8 decibels higher than the single engine (quite noticeable to the ear). Some of this difference may have been attributable to the fact that we tested on different days, both of which were windy, with considerable variations in measured noise levels depending on the direction of travel.

    The single engine also racked up better fuel-economy numbers. At a moderate trolling speed of about 7 mph, the single engine is capable of better than 3.3 miles per gallon (mpg) while the twins just edge over 3 mpg. As one bumps up the speed (to troll lures instead of dead bait, perhaps) to about 10 mph, the single still manages almost 2 mpg quite good considering how much more water drag the slight speed increase adds. At this higher trolling speed, the twin-engine gas mileage drops down to about 1.5 mpg. That’s a big difference when averaged over time. On a single day of trolling, you’re talking about burning 10 or more gallons extra with the twin-engine setup.

    The only place the twins even come close to operating for the same cost as the single is at cruising speeds. Still, the single edges the twins at every speed. Using our comparison table, we can see that the single 225 gets better fuel mileage at all cruising speeds. The advantage varies from just about even to as much as two-tenths of a mile per gallon.

    Finally, the single engine boat is about 2 mph faster at WOT.


    Conclusions

    Weight is an issue, too. The twin package adds over 200 pounds to the total weight of the boat and in a bad location, too, right on the transom. With less weight hanging off the transom, the single-powered boat seemed to jump on plane quicker and easier, plus it held its plane at a lower speed.

    And then there’s cost. The total retail price of the boat powered with the twin 115-hp Yamahas is $1,600 more than the same boat with the single 225-hp Yamaha. Also consider the greater maintenance cost of caring for two engines. You’ll need to change oil on two engines instead of one. Granted, the smaller 115s hold less oil each, but combined, they require more oil than the single. Plus, you have two oil filters, two fuel filters, two lower units, and more time spent paying the mechanic.

    Another important factor to consider is that the single operated at lower rpms than the twins at every speed we tested. When comparing internal combustion engines like these, the one that runs at lower rpms will usually offer more efficient operation and enjoy a longer life. All this adds up to more money spent on the twins over time.

    Bottom Line: The single 225-hp engine delivers better performance at a lower price.

    Curtesy of Powerboats web site.
    Tennessee

  2. #2
    Member GOT TOYS's Avatar
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    Default Great info

    I used info such as this in my decision to go big single over twins. There are several more reasons than listed. Less drag in the water, less broken parts if you hit a log or rock...the list goes on.

    The only reason I could find that was a plus for twins, was in-port maneuvering. If you know what your doing, it can help docking in high wind.

  3. #3
    Member Dan in Alaska's Avatar
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    Thanks for the post, Snowwolfe. I've often wondered how these different motor packages compare. Twin 115's seem to be really popular in Alaska, but I always thought a single 225 w/ a small kicker would be a better set-up. I am glad PBR did a test like this.

  4. #4
    Member kaisersosei's Avatar
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    Smile My two cents

    I wrestled with these options when I went looking for a boat and came away with twins anyways for various reasons. When you have a problem on the ocean, you can't just walk back to the nearest service station and you risk the lives of all aboard. I think whether people want to admit it or not, the fact that it is such a popular option to have twins in Alaska speaks for itself. Here are my justification on the twins side.

    1. While people may argue that contaminated fuel is mostly the culprit behind problems with motors in the sea, there are many other parts and pieces that do go wrong with a motor. I have had the experience and know of others that have also. Things like a parts failure or an accidental lower-end damage from a rope or debris do occur and may effect 1 motor and not the other.
    2. If you wanted to be ultra-safe, you could isolate the tanks but I think it is a bit much for me.
    3. The cost difference between a large main and a kicker or twins is in relative terms, not significant when you consider that the total package may be the difference of $110,000 or $115,000 for a well-equpped alum boat in the 26 ft plus range. In fact, payments on a monthly basis may be just a couple of dollars more.
    4. I would add that when you get twins, you should get it so that you can get "on step" with just one of the motors in normal conditions even if it means changing out props to accomplish it.
    5. Maintenance is more and economy is less with twins but I bet you nickels to dollars that if two boats were for sale in May identically equipped except one with twins and one with large single and kicker, the twin equipped boat would sell much faster.
    6. Finally, if you have ever been out 70 miles from port in ugly weather with engine problems at 3pm when most others have left to head back to port, the $5 or $10 per month for twins is cheap. In the last few years, I have either experienced or know of others who have experienced problems from blown fuses, failed hoses, fuel pump problems and other issues. Speaking of cost and efficiency and maintenance, do you know how much it costs to get a boat towed in from Montague island and the costs of not being able to make it back home on Sunday night to go to work in the morning? I do, and mine was a fuel pump failure.

    As for me, I go for twins.

  5. #5
    Member Sierra Hotel's Avatar
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    Default

    I read this report and was convinced by it - but still opted to go with the twins. Based on feedback from other folks on this site I was ordering the twin 150's instead of the 115's. Dan at Dewey's talked me into staying with the 115's and offered to change out the engines (I pay the difference in price of the engines only) if I wasn't happy - a pretty good offer.

    I put my order in today:

    26' Hewescraft Alaskan
    Twin 115 Yamaha's
    Garmin GPSMap 3010c
    Garmin GSD22 Sonar Unit
    Garmin GMR18 Radar
    Garmin GMS10 Network Hub
    Ace Pot Puller
    Powerwinch windlass
    Cannon downriggers
    Radar Arch

    Should be ready 12 May - will be on the water soon thereafter.

    Cheers,

    John

  6. #6

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    Let's see the results, with one engine on each boat shut down.

    I suspect the single engine boat will win in fuel burn and noise categories, but do pretty bad in performance.

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    Default single vs twin in trolling

    Other than maintenace costs, which isn't all that much, I noticed they didn't try to troll with one engine out of the water on the twin setup. Why is this? Surely a single 115 has enough power hold allmost any boat at trolling speeds. How would economy numbers be then? Also, economy at cruise wasn't too far off for each engine, and 2 mph at cruise isn't that big of a deal when talking about 20+mph. Also, I agree. If a singl 115 with the most aggressive prop available would put the boat on step, wouldn't it be worth it to make it home for dinner? That being said, it is very cool to keep both motors straight, one in forward, one in reverse, and spin a full circle around the transom.

    Chris.

  8. #8
    Member Alaska Gray's Avatar
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    Default

    Thank for the info
    Living the Alaskan Dream
    Gary Keller
    Anchorage, AK

  9. #9
    Member Dan in Alaska's Avatar
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    I own a 22-foot Hewescraft with a single Yamaha 115. I often think about upgrading to a 24 or 26-footer, and I think I would choose a big single vs. small twins. Here's why....

    My 115 has a tough time getting my 22-footer on plane with 6 people and a load of fish. If a 115 really struggles with a 22-footer, there is NO WAY a single 115 will plane a 26-footer. In this case, if an engine goes out, the one good engine won't get you home much faster than a kicker. You're still going to be limping home.

    If I were going to go with a twin engine setup, with reliability & safety being my main concerns, I would make sure each engine was big enough to plane the boat by itself. Otherwise, it just doesn't make sense to me to go with twins. Look at the charter boats. They are not running small twins; they're running BIG twins. Their charter boats don't need 450 - 500 horsepower....they just need 225 - 250 horsepower to work ALL THE TIME.

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