2025 suzuki DF115: MORE POWER

[LittleSumpin]

Has anyone tried to modify a DF115 into something closer to a DF140?

They both seem to have the same 2.0L blocks, so is it just the ECU, CAM shafts or some other black magic that makes the 115 into a 140?

( if possible ), is it easier with the mechanical controls or the drive by wire BG version?

Can you push the DF115 out to the 6,300 RPM limit like their Stealth line, to gain some HP ?

Thanks in advance

[cdbxyz]

I think they also have different air intake and 140 has an oil cooler.

[willk]

There are some who would say there IS no difference between those engines. The 140 is reputedly considered to hit well below 140hp. Not worth tinkering with IMO.

[LittleSumpin]

How about the 115 stealth vs the base 115. Seems they are just allowing the stealth line to rev from 6,000 rpm up to 6,300 rpm to gain on the power curve. Has anyone tried to boost the top end of the RPM range ( perhaps it sounds simpler then it actually is to achieve ).

[craigh]

I had my 1 year old Suzuki 40hp chip tuned to 60+ by West Wales Tuning. Sent the ECU away and they advised on removing a restrictor.


For me, the 40,50 and 60 are basically the same engine with diff ECU. Cost


Massive difference to performance.


I'm sure they would advise what is possible.



In fact, Thier website suggests they have done it before


https://westwalestuning.co.uk/suzuki-df115-remap/

[craigh]

Submitted before I finished editing - Cost £400 ish

[Pikey Dave]

Yup
In “theory” the 115 could be hitting the 126hp mark, whilst the 140 might only be delivering 126hp

[LittleSumpin]

Thank you Sir !

[Limecc]

Gen2 DF115 hasn't got much spare to give compared to the latest Merc 115 (JB Mechanical have seen 133 vs 163 hp). Should be no problem getting the rpm limit raised though, in fact just had it done myself.. Westwalestuning are UK's premier marine remapper. Martin really knows his stuff so if 140 hp is possible he can do it.

P.S. https://www.facebook.com/10003121732...0984762952092/

[jonp]

I looked into sending my ECU off for a remap which would have been around $1200 here in Australia. On top of that is the cost of re-propping which starts to creep up in total cost for a gain of around perhaps 10hp and 2-3mph at most.

I also saw a few negative issues of engine failure after tuning which put me further off the idea. I also had a $1600 remap done on my 3lt diesel Isuzu which followed with and constant run of engine issues from there on.

Here's a link to a place that may be able to advise you https://outboardtune.com

What boat size and what performance issues are you having ? Have you experimented with raising the engine and different props ?

[LittleSumpin]

@Jonp

Thank you Sir for your feedback and advice.

My RIB is a new boat purchase, and its max HP ratting is 115.
She is still getting built at the factory.

While looking at the Suzuki 115BG vs the 140BG, I was just curious if there was a relatively simple was to increase the power closer to the 140 or even the 115SS. The reason I did not go with the 115SS, was the lack of the additional drive by wire controls on Suzuki's SS line in this HP range. That drive by wire is something to behold! There is no going back for me

The RIB in question is the Highfields Sport 560
She will typically carry 2 to 4 people with a light to medium load out.
I am hoping to get at least 40 mph out of her. Any faster and the wife wont ride with me

I am hearing that a good starting point for the prop might be something like a 3 blade x 13.7/8" - 14.0" x 20 or 21. Was also considering a 4 blade as a back up & for when I need to pull some teens behind the boat.

[Stewy]

Did you not look into the mercury pro xs? That apparently puts out 126hp

[LittleSumpin]

@Stewy

I did look at the Mercury's Pro XS, but 2 items were deal breakers for me.

1) No digital controls

2) Quality level has gone south, not the Company it once was.
They tried to scale up to meet the demand around the COVID time, and they hired anyone with 2 legs to work there. They are paying a heavy price now. Perhaps the next boat build it will be deferent.

[jonp]

Originally Posted by LittleSumpin

@Jonp

Thank you Sir for your feedback and advice.

My RIB is a new boat purchase, and its max HP ratting is 115.
She is still getting built at the factory.

While looking at the Suzuki 115BG vs the 140BG, I was just curious if there was a relatively simple was to increase the power closer to the 140 or even the 115SS. The reason I did not go with the 115SS, was the lack of the additional drive by wire controls on Suzuki's SS line in this HP range. That drive by wire is something to behold! There is no going back for me

The RIB in question is the Highfields Sport 560
She will typically carry 2 to 4 people with a light to medium load out.
I am hoping to get at least 40 mph out of her. Any faster and the wife wont ride with me

I am hearing that a good starting point for the prop might be something like a 3 blade x 13.7/8" - 14.0" x 20 or 21. Was also considering a 4 blade as a back up & for when I need to pull some teens behind the boat.

Ive owned a few Suzukis (five in fact). The last one was a 140 2014 model which was the engine I found quite lacking. On a 5.4m boat I ended up experimenting a fair bit with props and engine height mounting. To reach full rpm I went with a 17 pitch solas stainless for max speed but found a 15 pitch 4 blade best overall performance. The 4 blade lifted the back out of the water for quicker take offs and better low speed holding as well as better rough water control.

I often end up with engines in that horse power so keep a selection of props rather than try and sell them and deal with scammers. The best prop on my current Yam f115 is the mercury x7 4 blade spitfire in 15 pitch, which I have on a 4.4m centre console, which makes me think a 21 pitch might struggle if you are carrying load on your boat. Do they prop test and exchange for free with new outfits ?

[LittleSumpin]

@JonP

Unfortunately they don't typically offer prop exchanges here where I live.
I know there is a place out of state, that offers prop exchanges and recommendations. Only catch is, that you pay for shipping and agree to purchase one of their props. Not a bad deal in my book

I agree, I will keep any props I might accumulate in the coming years.
I have actually considered one of the Sharrow props as well. They have a 30 day love it or return it policy too. The price is still VERY HIGH, but has come down considerably since they started expanding their operations.

I truly appreciate everyone's feedback and recommendations.
The RIB category of boats is really just starting to take off here in the States.
So not a lot of folks to collaborate with locally.