Upgrade 9.9 suzuki motor

John Thompson · Jun 28, 2023

Asking 2023 suzuki 9.9 upgrade kit is there one for the 2023 year

airshot · Jun 28, 2023

To the best of my knowledge, the four strokes are difficult to get the power up, to many parts and pieces and expense! The older two strokes were pretty simple, usually just a carb change.

InSaneFisherMan · Jun 28, 2023

John Thompson said:
Asking 2023 suzuki 9.9 upgrade kit is there one for the 2023 year

Simple and 2 parts.
Remove 9.9 restrictor plate and install 20hp flame arrestor. Gives you about 15hp.

To get 20hp, replace 9.9 ECU with 20hp ECU, of same year and motor type.

GYPSY400 · Jul 7, 2023

airshot said:
To the best of my knowledge, the four strokes are difficult to get the power up, to many parts and pieces and expense! The older two strokes were pretty simple, usually just a carb change.

Now you've learned something.

I think suzuki is the only motor this can be done too though.

Ben beds · Sep 6, 2024

Hi New here just purchased a Suzuki DF9.9B
if I just drill the restrictor plate and leave the original ECM is there any negative to this, I am just looking to get my boat on top of the water I am hoping that that would work not worried about rpm as not looking for wide open power
any feedback would be great

Zum · Sep 8, 2024

Ben beds said:
Hi New here just purchased a Suzuki DF9.9B
if I just drill the restrictor plate and leave the original ECM is there any negative to this, I am just looking to get my boat on top of the water I am hoping that that would work not worried about rpm as not looking for wide open power
any feedback would be great

I have no first hand experience with this...thought Id start off with that.
I frequent a few different forums and read that its legit...also on youtube, you can search it, theres a few videos showing whats done.
To me if I had the issue your saying , id buy the cheap part needed and not wreck the orginal ....that way you could always put it back
Again, Not telling you to do it ...

Edit...never watched any videos so I decided to...this guy changed the ECU as well, went from 13mph to 22mph.

Again, not sure what just removing the resister plate would do but for as cheap as a new flame arrestor is , dont think id drill the orginal out.

InSaneFisherMan · Sep 8, 2024

Ben beds said:
Hi New here just purchased a Suzuki DF9.9B
if I just drill the restrictor plate and leave the original ECM is there any negative to this, I am just looking to get my boat on top of the water I am hoping that that would work not worried about rpm as not looking for wide open power
any feedback would be great

Yes it will work.

At WOT you will hit RPM limiting and motor will surge (depending also on prop). The 20hp ECM changes the RPM limit from 5700 (9.9) 6000 (15) to 6300 (20).

For warranty issues, I would have kept the original.

Still Afloat · Sep 8, 2024

The restrictor plate is cheap. Just buy a new one so you can go back if needed.

I’ve got newish (‘22 or ‘23) Zuki 9.9 with the 20hp ECM and arrestor. It works great and I’d do it all over again if I picked up another 9.9.

By the way, they don’t call it a restrictor plate on a 20, it’s a flame arrestor.

InSaneFisherMan · Sep 9, 2024

Ben beds said:
Hi New here just purchased a Suzuki DF9.9B
if I just drill the restrictor plate and leave the original ECM is there any negative to this, I am just looking to get my boat on top of the water I am hoping that that would work not worried about rpm as not looking for wide open power
any feedback would be great

I would keep the original restrictor plate and purchase a flame arrestor. The flame arrestor is like wire mesh.

If you ever have warranty issues, just reinstall the original back.

See other post about over revolution limit caution system.

InSaneFisherMan · Sep 9, 2024

InSaneFisherMan said:
Yes it will work.

At WOT you will hit RPM limiting and motor will surge (depending also on prop). The 20hp ECM changes the RPM limit from 5700 (9.9) 6000 (15) to 6300 (20).

For warranty issues, I would have kept the original.

Just want to correct the numbers per the service manual.

Over-revolution limiter:
9.9b 5900 r/min
15A 6200 r/min
20A 6300 r/min

The ECM will cause an intermittent fuel injection signal and cause the motor to slow down.

Jarrett Nash · Sep 24, 2024

InSaneFisherMan said:
Just want to correct the numbers per the service manual.

Over-revolution limiter:
9.9b 5900 r/min
15A 6200 r/min
20A 6300 r/min

The ECM will cause an intermittent fuel injection signal and cause the motor to slow down.

Can you prop it to maintain less than 5900 and still get most of the conversion benefit?

InSaneFisherMan · Sep 24, 2024

Jarrett Nash said:
Can you prop it to maintain less than 5900 and still get most of the conversion benefit?

Hopefully someone that knows more about props will chime in, but the Rev limiter system will force you lower the rpm's when it hits the limits.

My understanding, is a WOT, you do not want to exceed rpm rating for you motor and damage the engine. It can be done through prop pitch, less throttle, boat weight, and Rev limiter.

From memory, I think I gained 2 mph, by installing flame arrestor and keeping original prop before hitting rev limit.

Still Afloat · Sep 25, 2024

I went up an inch in pitch from the stock 9.9 prop but, I’m sure that will vary will the application. Here’s my notes from testing with a new bare bones Lowe 1448M:

Stock 9.9 prop.
9.25 x 9”: 4111-093-09A. 23mph at approximately 3/4 throttle 6350 rpm. Hitting rev limiter.

Solas Amita 3 props
9.25 x 10”: 4111-093-10A. 26 to 27 mph at WOT, running 6100 - 6150 rpm

9.25 x 11”: 4111-093-11A. Too much pitch. (Available for sale or trade.)

I’m not that impressed with the Solas Amita line of props. The Suzuki prop was higher quality. A better prop might increase performance.

DaleH · Sep 26, 2024

All Solas props are crap, LOL!

LDUBS · Sep 26, 2024

Aw man, I think my "Honda" prop is made by Solas.

Still Afloat · Sep 26, 2024

DaleH said:
All Solas props are crap, LOL!

No argument from me.

So who is a good prop mfg in the 9.9 to 30 range?

DaleH · Sep 26, 2024

Still Afloat said:
No argument from me.

So who is a good prop mfg in the 9.9 to 30 range?

My favs are the pressed aluminum ones by Turning Point that are almost as thin in blade section as SS ones. But never overlook OEM ones.

LDUBS said:
Aw man, I think my "Honda" prop is made by Solas.

For the Honda ones IF made by Solas, I'd be quite sure that it was made to Honda's specs, so that's still likely a good choice. And I've not tried them all, and only on OMC or Nissan OBs, but they were always in last place for performance for those I've tried on the same OB/rig.

So I guess I should have re-worded my smart azz comment as "There are better choices ...", sorry

!

LDUBS · Sep 27, 2024

DaleH said:
For the Honda ones IF made by Solas, I'd be quite sure that it was made to Honda's specs, so that's still likely a good choice. And I've not tried them all, and only on OMC or Nissan OBs, but they were always in last place for performance for those I've tried on the same OB/rig.

So I guess I should have re-worded my smart azz comment as "There are better choices ...", sorry !

No worries. I recently went up a pitch otherwise would have no idea where the prop comes from. The box says "Honda-Solas", engineered by Honda.

Still Afloat · Sep 27, 2024

Thanks for the tip on Turningpoint.

I definitely saw a bigger rpm drop than expected when going from the 9” pitch Suzuki prop to 10” Solas. It would be interesting to try the same prop size in both brands.

Upgrade 9.9 suzuki motor

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