I am recanting, and this time for good.
I have been reading dozens and dozens of posts on the single vs. twins question. I have also downloaded engine/boat/speed/fuel usage charts until I am cross-eyed.
I kept thinking that there had to be a reason why so many of our northern neighbors are ordering the 25 with the single and kicker combo.
Experience and common sense tells us that the single, HP for HP is both faster and more fuel efficient than twins,(due to less drag and weight) while twins may well have an advantage in low rpm acceleration.
Where the Honda 90's are concerned, a further prioblem became apparent, at least for me. The Honda 90's only provide a meager 16 amps each of electrical power. That's only 32 amps with twins at maximum throttle. That's not competitive in the electronic age. As an example, Suzuki's 40 hp models exceed that. A single Suzuki 90 provides 40 amps; two and one-half times as much as a Honda 90.
Looking at a lot of charts also taught me a few things. There is a lot more involved here than just picking color and horsepower.
I looked at various other manufacturers, all of whom were cheaper than Honda in the sizes I am considering. I wanted to stick with Honda if possible, though. The question then became which Honda?
The official C-Dory brochure lists mamimum HP for the 25 as 200. Fine. Everyone makes those, including Honda. A lot of my boating will be in the Delta where the water is often glassy smooth. A big engine would be ideal for that.
It did not take long to get over that idea. I could not find performance tests of the different engines on the same boat, but I managed to get the size and weights fairly close.
Comparing the twin 90s to the single 200, the 200 was generally superior at displacement speeds on both MPG and GPH. At planing speeds the twins were superior in those categories, although not by a lot at similar speeds. Obviously the 200 would be faster, but that's not a big deal on a CD. The 200 has a 60 amp alternator, though, almost twice that of the twins combined.
Still,the 200 and a 15 kicker would cost almost 2 grand more, weigh only about forty pounds less than the twins, and use more fuel at normal speeds. Not a good choice.
I would have to run the 115 HP too hard at cruise, so it was not a good choice for me.
That left two engines, the 135hp and the 150. Both use the same block; a 2354cc double overhead cam 4 cylinder based on the Honda Accord.
Normally, when confronted with a choice between engines with the same displacement, i will opt for the lowest peak HP, particularly if the boat is heavy and/or not a speedy type. The lower peak HP usually means more grunt at low revs, which makes sense on a CD.
There is more to this than is apparent, though. Honda has just made its VTEC system available on the 150. Previously, only the 225 had it. As most people know, their VTEC system varies the intake valves according to rpm. Low lift and duration at low revs for outstanding low speed torque; then providing greater lift and valve opening duration at higher speeds for higher power. Best of both worlds. It's relatively trouble-free. Honda and BMW have been using it for years in cars.
Both of those engines also have Honda's "lean burn" fuel injection for improved mileage at cruise. A new dual stage induction system also should help performance at all speeds. The cooling system is also improved on both. Alternator output is only 40 amps, but that's still 25% better than the twins.
Dry weight is listed at 485 pounds. roughly 100 pounds heavier than a 90, but unlike the 90, you only need one.
The performance charts were instructive.At 1500 rpm the twins were going 6.6MPH at 1.6 GPH. The 150 made 5.9 MPH at 1.0GPH.
At 3500RPM the twins were going 24.4MPH and burning 7.8 GPH. The 150 was going 20.8MPH and burning 4.4GPH.
At 4500 RPM the twins were going 28.9MPH and burning 9.6 GPH. The 150 was going 30.2MPH and burning 7.5 GPH. Results were similar at most other speeds.
These results are imprecise, as I stated, because the boats are different. The lightest boat weighed 4300 pounds(the 150), while the heaviest (the 200)weighed 4900. Different bottom configurations, as well.
I think some general conclusions can be drawn, though.
This Honda 90 is old-tech. It has carbs, no VTEC, no double induction, no lean burn, old style cooling, and low alternator output. It will likely be updated soon, and this "dated" engine may not be highly sought after on the used market. It is simple,durable, and easy to fix, but I'm guessing that prospective buyers will want to know if the boat you are selling has the old engines or the new ones. Just my guess...
A new 150 plus a 15HP kicker will weigh approximately 160 pounds less than the twins, and cost about $1300 less as well.(according to my price list from the boat show) It should be about as fast, maybe faster, will use considerably less fuel, will allow the factory swim platform if desired, and should be cheaper to maintain. Probably save on controls as well.
The 135 plus 15 kicker is another $1300 cheaper, for a savings of about $2600 over the twins. I personally like the 150, but for many the 135 makes more sense.
I think I see why the big single and kicker isselling so well.
I'm changing my order Tuesday.
