detuned outboards

[marco422]

I never quite understood the rationale behind a manufacturer producing two outboards with the same displacement but different power ratings (eg Honda 40/50). What do they do to change the power? How do they make the lower power unit cheaper? Under what circumstances would you use one as opposed to the other?

[Spike]

There are alot of ways to change the HP on a engine. Different carbs, remapping the fuel injection, cam profiles, ignition changes, intake, and exhaust mods, are just a few.

Chuck

[Larry H]

When I worked in the O/B business a ways back, I asked the tech rep why motors built on the same displacement powerhead cost less for the lower hp.

His answer was that O/B motors are sold by the horsepower, not the cubic inch displacement. So if the manufacturer is making a good profit on the lower hp, then they are making a really good profit on the higher hp! (assuming the same displacement)

Larry H
Retired O/B mechanic.

[jennykatz]

Why do Auto makers make different cars on same platform They can get more bang for the buck . Look at Suzuki they have a 70-80and 90 on the same cubic in . eng .By remapping the computer or the valve opening and closing they can change the hp ratings . My 06 suzuki 90 was more like a 100hp the mfg are allowed to fudge 10% hp. ratings .Now that same eng is called a 100hp for 09 .The yamaha 150 is really turning out about 164hp. Find the eng you like dealer support features etc. then try to buy the lower hp rating in that family . This way you get the most hp for the least amount of money

[Wefings]

Unless of course you want more power. Outboard prices are also driven by which ones they made too many of .
I ran the new Suzuki 90 yesterday on a 19 Angler . It was break in day so no blistering speed runs yet . The Tach is also defective , so we will get more data out this week . Also still playing with prop styles and such . Tried an 18 P Powertech TRO 4 blade . It was OK , but without accurate tach I couldn't really tell what it was doing . Lots of steering torque , will go to a 3 blade Solas 19 P next . Still haven't found a good reason to use a 4 blade or a plastic prop on a C Dory except as a spare.Probably be able to do a before and after Permatrim test as well . The 19 will benefit control wise I am sure.
Marc

[forrest]

They really don't detune outboards. Manufacturers increase performance of their base model at the upper RPM's to gain horsepower at maximum RPM. I think Honda does it by electronic valve timing to increase air flow at max RPM. In other words you don't receive the benefits of the higher HP rating unless you are close to running at full throttle. If you don't power around your C-Dory at full throttle you would never know the difference between the different horsepower models with the same cubic inch displacement. There really is no substitute for cubic inches to increase HP in normal RPM operating range. This is just my opinion as a consumer, I'm not an engineer.
Forrest

[thataway]

Early on there were lakes which restricted outboards more than 10 hp. Thus many outboards were made on the 15 hp head, and restrictor plates were put in, and it was "de-rated" to 9.9 hp. (May be still some lakes which are restrictive).

The newer and bigger engines often have variable valve timing on the higher HP engines. Same basic engines, but rating at higher speeds, with the Variable Valve timing, they get more HP out of an engine.

The profit motive certainly exists.

[flrockytop]