[Carlsward]

I just upgraded my -03, ZX9 R with a Yoshimura RS 3 slip on.
So now I need to change jets, any ideas guys ?

Its currently running a bit un even / bumpy up to 2800 rpm

 

[e1_ZX-9r]

I just upgraded my -03, ZX9 R with a Yoshimura RS 3 slip on.
So now I need to change jets, any ideas guys ?

Its currently running a bit un even / bumpy up to 2800 rpm

What you're after has to be accomplished on all three fuel circuits. Adjusting the mains only will do little about the common 2,800 RPM lean surge bumpiness.

Pull and drain your carbs, then:
1) set the pilot air screws to 1 1/2 to 1 5/8 turns on all four carbs.
2) bump the jet needle up with a washer shim as outlined in the 9R section. Anything from 0.5 - 1.3 mm will do the trick.
3) [optional] up the mains 3% (? x 1.03), which for stock 165/160/160/165s would mean you'd only need to buy two new Keihin 170s...and move the 165s to the center two.
4) buy a good quality throttle-body synchronization tool, like a CarbTune Pro 4 and synchronize the carb bank, also as described within.

Just be careful. Your erection will last for more than a few years and you should consult with your physician.

 

[Carlsward]

Awesome e1 !!

I really appreciate your detailed reply
I m usually one of those lazy farts that likes hanging around and watch while other people works on your bike.
But this time I actually gone get my fingers dirty.

Cheers

 

[e1_ZX-9r]

So I take it, based on what you wrote in the other thread, that you were able to tune the jetting to your satisfaction.

If you don't mind explaining and helping others who might be interested, what did you end up with?

 

[Masta Squidge]

I thought the center two should have the larger jets?

9s are different?

 

[e1_ZX-9r]

repost

Certain models are. In this case the OP's 2002/2003 F1/F2. Same for certain ZX-11s.
*********************************************************
I'll see if I can get this right. Always assume a typo and get your own shop manual to use as the primary source of repair & specification information.

Model.........ZX-9rB..........ZX-9rC
main jet.US...#190...........#155
main jet.other#200
jet needle....staggered.....same
pilot jet......#35..............#38
pilot airscrew.(1.5 +/- 1/4)...2.0
turns

Model.........ZX-9rE..........ZX-9rF
main jet 1/4...#160...........#165
main jet.2/3...#165...........#160
jet needle....same............staggered
pilot jet......#38..............#38
pilot airscrew.(1 5/8).......(unknown)
turns

Float height for E is 4mm +/- 2mm. All others 13mm +/- 2mm.

The F model main jet stagger is correct, it's the reverse of the E. I have a spare set of these CVKD carbs and visually confirmed the sizes. Strange, I know.

<here>

 

[Matty]

Hi I have 2000 model and was thinking of removing end cap in standard muffler, removing mesh in filter. So would you suggest the same carb settings to start with that you mentioned for yoshi muffler?
Thanks Matt

 

[Masta Squidge]

Hi I have 2000 model and was thinking of removing end cap in standard muffler, removing mesh in filter. So would you suggest the same carb settings to start with that you mentioned for yoshi muffler?
Thanks Matt

No, we suggest selling the stock muffler to someone who will appreciate the OEM parts and buying a slipon. I hate it when people just gut the stock exhaust personally. It sounds bad and ruins a damn expensive part.

Unless you have some insane restriction on aftermarket exhaust that is. In which case, rip that thing apart and stick it to the man.

 

[Matty]

Viper

Good advice cheers
Put a viper slip on that was selling on Trade me for only $60 ,just needed a sand up as few scratches
Took mesh out of air filter
Did the washer trick on needles to richin it up
And wow smoother good power
Probably should do air mixture job and dyno

But runs bloodly good really for what I have changed
I did notice on street at around three grand its not perfectly smooth
Cant wait for next track day to try it out properly

Just have to sort out my warped discs as has shocking high speed shudder
So many choices of after market rotors, not sure what to buy

 

[Claps1775]

I am jetting my 9rC2. I am hoping to get a slip on. What am I looking at for jets and what company too?

To some people its a rocket.
To others it's freedom. (zx9r)

 

[quisp]

Ivans