Suzuki GS500 and GS500f
04-13 (and some 01-02-03)
Factory Pro Series "S11"

The lightweight GS is one of the lightest entry level 500s around. Delivering pretty good top-end power with a generous serving of low-end and midrange (when the carburetion is tuned).
The Carb Recal Kit perks up the low-end and midrange power and response for quicker warm-up and more response.


Carb Recalibration kit

 (and some 01-02-03)

for stock airbox

1. Choose your shipping method



Standard drop-in carb kit

The standard jetting is somewhat lean and off-idle, takeoff drivability suffers - (but mileage is GREAT!!!)

The kit, when properly tuned, adds more low-end / midrange and if the proper main jet is selected, more top-end power.

Easy to install and tune - no slide drilling.


 Our S11 kit is for 500s with carbs with FOUR float bowl screws.

Our S10 is for carbs with TWO float bowl screws - 2  screws? click here


Positive feedback rating    Carb kit Feedback
I just want to say thank you for the S11 kit. I can really tell a difference from the stock set-up. Throttle response in incredible now compared to the OEM.

My mechanic decided on the 137.5 main and the clip on the second setting. I have a K&N drop-in air filter, but he left the restrictor in because I have a stock exhaust. Maybe next summer I can upgrade to a performance exhaust as I still have the 140 and 142.5 jets left over. Thanks again.
Pat Pentecost
April 2009

Positive feedback rating     Pipe + Jet Kit
The biggest performance problem with the GS 500 is that it doesn't breathe. There are aftermarket racing pipes available from Yoshimura (, Hindle ( and Vance & Hines (  These run $350 to $400.  The experienced tuners who build and tune engines for BIR racers prefer the Yoshimura or Hindle.  According to them, the V & H is an older design that makes less power on the dyno than the larger-volume pipes.  The V & H is noisier than the others too.  If you change the pipe, you will need to install a jet kit.  Dynojet ( and Factory ( have kits for the GS 500.  I prefer the Factory kit because they don't ask you to drill holes in your slides, and they use real Mikuni jets with legible, meaningful numbers.  The Dynojet kit contains their own style of jets that have some bizarre numbering scheme so you can't look at them and figure out what the hell they are relative to a stock jet.  That's great if you're never going into the carburetor again, but if you want to do more carb tuning at some point, it will help if you are using the same numbers as everyone else.



Positive feedback rating        Hi Marc,
I have very good feedback for you "on a 2007 Suzuki GS500F" with your jet kit installed, a k/n air filter w/o restrictor, and a yoshimura slip muffler, in long island, NY altitude; the following setting are on point. 22.5 pilot jets with 2.5 turns out on a/f screws. Needles at 2nd clip, main jet 140, and floats at 14mm.The bike pulls so different it feels nothing like stock and I only have 250 miles on it. Consider these settings as good as it gets!!!

Please forward these setting to all 07' GS500 owners !!!


CRB-S11-3.0  01-13
(for 4 float bowl screw carbs)
(and maybe 01-02-03)
for when you've removed the stock airbox
(for 2 screw float bowl carbs)   

1. Choose your shipping method



Config 30
Carb Recalibration Kit

For when you are running a K&N RU-2790 open filter.

This carb kit, when properly tuned, adds more low-end / midrange and if the proper main jet is selected, more top-end power. Easy to install and tune - no slide drilling.


Long Boy Fuel Screw 
pn: CRZ-SCR-4030-M
 with 2 new screws, springs, washers and o-rings

1. Choose your shipping method


"Long Boy"

Finger adj. extended Fuel Screw Kit

Frustrated with trying to find an "almost 90 degree"  screwdriver to fine adjust your fuel screws for best idle and cruise?
Use Factory Pro's new "finger adjustable" fuel screws to adjust fuel screws for best throttle response. Traveling to high altitude? It's easy to lean out the lowend temporarily.

Make your life easier!

Remove old short stock fuel screws, old orings, old washers and old spring. The o-ring might be stuck in the carb, so, take a light and make sure it's really out if it didn't come out with the screw (or you can't find it after you took out the screw)
Use a small bent wire to pull it out if it doesn't drop out. Keep the old parts for "spares".

Fuel screw assembly comes with:
2 Long Boy fuel screws
 2 new o-ring
2 new washer
2 new spring


Carb Setting Tools

TL-float height gauge   $59.95

1. Choose your shipping method


The only way to accurately measure float heights. Works on nearly every carburetor.


Race setup


True Rear Wheel Horsepower® Factory EC997a Eddy Current Dynamometer


Owner's bike pics








Absolutely NO carb parts sold in California.

New and improved Suzuki Teka SFI  2

with new TPS display and "MMT" Memory Module Tuner

Finally - Quick, easy, cost effective Suzuki tuning with no expensive "add-on boxes"
Suzuki cruisers and sportbikes

Please click here for more info

Contact Factory Pro
M-F, 9am - 5pm, Pacific time, -7 or -8 GMT

800 869-0497
 USA and Canada

415 883-5620

parts information

EC997 dynamometer information

Product Support /Tech SECTION
click here


Mailing / Shipping address:

Factory Pro
101c Roblar Drive
Novato, CA

And most importantly
Restart back at the HOME page and click on the red box in the top left to find the bike that you want parts for...
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EFI and Carb Tuning - Most all FI and carb tuning

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The extension of the laboratory for engines of the Swiss Federal Institute of Technology was completed in about 1935. Its architect was Rudolf Otto Salvisberg (1882-1940). He had a successful career in Berlin but returned to Switzerland after the advent of the Nazis. His architectural style was somewhat similar to that of Erich Mendelsohn. The staircase of the laboratory is in normal use but well preserved.
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