2021 Susuki 4 stroke 25hp and 30hp Outboard difference?

[jdmcpha2]

Hi,
Looking at purchasing a new engine and the Suzuki is available so it's what I will buy.
The 30hp is $700 more than the 25hp.
When I compare the specs, they are the exact same motor. Same piston stroke. Same displacement. Same weight. So what makes the 30 a 30?
Can I get the 25hp and do a simple computer tweak or different carb to make it a 30hp?
Here are the basic specs of each.
Number of Cylinders: 3
Piston Displacement inches (cc): 29.8 (489)
Bore x Stroke inches (mm): 2.80 x 2.68
Maximum Output HP: 30
Operating Range (rpm): 5300 - 6300

Number of Cylinders: 3
Piston Displacement inches (cc): 29.8 (489)
Bore x Stroke inches (mm): 2.80 x 2.68
Maximum Output HP: 25
Operating Range (rpm): 5000 - 6000

 

[boscoe99]

Go and open up the parts catalog for the DF25 model. Then open up the parts catalog for the DF30 model. Compare the parts used on the two models. The parts used on the DF30 that are not used on the DF25 are what needs to be added to convert the DF25 to the DF30.

I don't see either of those models using carburetors.

I have never heard of anyone recoding an ECU for either of these models.

 

[matt167]

my bet is the camshaft is different, without looking at the IPL's. The ECU would be different because of it as well

 

[Bobobob]

Well from the Suzuki forum the consensus is the difference is a $12 air restrictor plate? (The 25 has one and the 30 has an open intake.)

30HP upgrade from 25HP 2021 New motor - Suzuki Outboard Forum

 

[jbcurt00]

Well from the Suzuki forum the consensus is the difference is a $12 air restrictor plate? (The 25 has one and the 30 has an open intake.)

30HP upgrade from 25HP 2021 New motor - Suzuki Outboard Forum

And as noted virtual no improvement, ran worse and swapped back to original parts.

 

[Sea Rider]

For $ 700 price diference there's a lot more parts involved than just an air restrictor. More HP more money involved.

Happy Boating​

 

[boscoe99]

For one, different ECU part numbers.

Fig. 310 - Rectifier/Ignition Coil - Suzuki DF 30A Parts Listings - 2020 - S/N 03003F-040001 to 03003F-04XXXX

Fig. 310 - Rectifier/Ignition Coil - Suzuki DF 30A Parts Listings - 2020 - S/N 03003F-040001 to 03003F-04XXXX, Suzuki Outboard Parts Catalog

www.brownspoint.com

Fig. 310A - Rectifier/Ignition Coil - Non-Remote Control - Suzuki DF 25A Parts Listings - 2020 - S/N 02504F-040001 to 02504F-04XXXX

Fig. 310A - Rectifier/Ignition Coil - Non-Remote Control - Suzuki DF 25A Parts Listings - 2020 - S/N 02504F-040001 to 02504F-04XXXX, Suzuki Outboard Parts Catalog

www.brownspoint.com

 

[boscoe99]

Well from the Suzuki forum the consensus is the difference is a $12 air restrictor plate? (The 25 has one and the 30 has an open intake.)

30HP upgrade from 25HP 2021 New motor - Suzuki Outboard Forum

Consensus is not always correct.

 

[matt167]

ANY change you do to any same displacement but different hp motor, needs to be reflected to the fuel mixture. That equates to different ECU part numbers in an EFI engine.. Now, perhaps Suzuki has tune files so they can just flash replacement ECU's or update a glitchy tune, just the same as car manufactures do, then you could possibly pay to have them flash the 30hp tune and knowingly void your warranty

 

[Bobobob]

Just passing on info from another forum, After looking at the two engines, I personally would choose the 30HP just for all the added features it has standard. On a side note however it would seem in the higher HP engines that most engines in a specific group are just detuned versions of the top HP engine with no major physical differences. Even the ECU's in the larger engines are the same part numbers.

 

[boscoe99]

Just passing on info from another forum, After looking at the two engines, I personally would choose the 30HP just for all the added features it has standard. On a side note however it would seem in the higher HP engines that most engines in a specific group are just detuned versions of the top HP engine with no major physical differences. Even the ECU's in the larger engines are the same part numbers.

Are you speaking of only Suzuki? This is certainly not the situation with 00% of Yams. There are a number of Yams of varying power levels in which the only difference is the ECU.

 

[boscoe99]

Just passing on info from another forum, After looking at the two engines, I personally would choose the 30HP just for all the added features it has standard. On a side note however it would seem in the higher HP engines that most engines in a specific group are just detuned versions of the top HP engine with no major physical differences. Even the ECU's in the larger engines are the same part numbers.

Are the lower power models detuned versions or are the higher power models tuned up versions?

In some Yams, the lower power models came first. Followed by the higher powered models.

 

[Sea Rider]

You can upgrade/detune any motor as long shares exact same CC powerhead as in this 25-30 HP Suzy example. A 30 HP motor revving with higher rpm due to more fuel intake usually needs more timing advance. Their individual 25-30 HP ECU's will takes care of both situations. Although the outside cosmetic look will remain the same, what's under the cowl it's other story.

Happy Boating​

 

[Bobobob]

Are you speaking of only Suzuki? This is certainly not the situation with 00% of Yams. There are a number of Yams of varying power levels in which the only difference is the ECU.

I was talking about Suzuki only, the (25-30), (40 - 60), (70 - 90), (115 - 140), etc. those groupings as far as all the data share the same exact powerhead. There may indeed be more differences between ancillary devices however to keep costs down the powerheads are the same. The 40-60 HP range users seem to have had years of trouble free use with just replacing the air restrictor plate to the one from the 60HP model and noticed a huge seat of the pants and speed increase in doing so. Fuel maps are designed in such a way as to allow safe and reliable operations at multiple altitudes so there is flexibility in the maps to compensate for more air and giving a boost in performance. Will you get 60HP from a 40HP motor with a $12 restrictor plate modification? probably not, will you enjoy a performance increase? real world applications say yes.

In the end however if you are buying an outboard, buy what you want/need. If you have an out of warranty outboard and buying a new one isn't in the cards, why not try and squeeze some extra performance out of it?

Sorry if anything I said seemed misleading initially.