Upgrade 9.9 suzuki motor

[John Thompson]

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

 

[airshot]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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.