Pablo's gs500 page
Jetting for 2001 models
R1 taillight install on 89-00 gs500
Clear Taillight Lens for 01-03 Models
My Local Canyons
What's it worth?
Progressive fork spring install-the lazy way
Rear shock swap information
More rear shock info-SV650 install
Suspension tuning 101
Installing Suburban-Machinery SV650 handlebars
Install an SV650 headlight
Converting standard 1/4 throttle to 1/5 throttle
Installing LED's in stock taillight
Uber Fender Eliminator
R1 Taillight on 89-00 GS500
Speedo/Tach light replacement
Better handlebar grips
Installing Buell turn signals - Rear
Installing Buell turn signals - Front
Flush mount rear (stock) turn signals
Installing a 2001 Ducati Monster fairing
Fix a broken oil filter cap bolt
General battery info
A Wal-Mart sealed battery?
Chain Maintenance
Installing SV650 Chainguard
Spark plug information
Installing a GSXR front end
Installing a GSXR swingarm
Installing GSXR rear passenger peg brackets
Installing an OEM Bandit 400 rear hugger
Installing a Bandit 400 rear wheel
Installing a GSXR rear wheel-simple swap
Polishing your wheels
"The Mystical Art of Tire Reading" and other tire info
General tire info for the GS #1
General tire info for the GS #2
General tire info for the GS #3 - mixing brands/types
gsJack's opinion on tires for the GS
Gearing and sprockets
Slip-on mufflers
Slip-on exhaust : using stock SV650 muffler
Installing an R6 tail
Installing GSX-R600 stock rearsets
Installing CBR600 stock rearsets
Replacing stock front pegs with CBR pegs
Replacing stock front pegs with Katana pegs
Why re-jet a stock US bike
More on re-jetting your carbs
Jetting for 2001 models
2001 and Newer GS500's have different carburetors
These recommendations come from member mjm from the GSTwin board.
They come stock with 17.5 bleed type pilots, a number 60 mid-jet and 127.5 main jets. The formunla seems to be -

STOCK - increase main jet one or two sizes, shim needle with a washer, pilot screws out to 3 turns (to start) - most of the cold bloodedness goes away. If it doesen't, then go up one on pilot.

K&N pods - Go up a few more sizes, and one more washer on the needle - I ended up at 142.5 before I did the exhaust.

KN& Pods, Slip-on and Ignition advancer - up a few more sizes on the main - either 147.t or 150. 

Another person on the board indicated that they were increasing the mid-jet to 67.5 - I [mjm] have no idea how that works out.
That other person is Piper5177 who says the following in regards to a Stage 3 jetting:
I have been messing with this for a little while, and I have just about got it. Changed the needles to the ones from the 89-00 Dyno Jet kit, DNO348. They are smaller than the stock ones since they are for a 33mm carb and not a 34mm. But since they are smaller, the pilot did not need to be changed. I set them on the fourth clip from the top. I changed the main to a 147.5, and it has great top end.
The only problem is with the smaller 60 main jet. Those jets take care of the mid range up to around 6500 RPM. With the higher volume of air moving through the carbs they lean out until the carbs hit the 147.5 jets. I ordered some 67.5 jets and those should clear up the little flat spot. I tried shimming up the needles some more, but since the jets are lean the needle doesn't help at all. I have Vance & Hines exhaust and the UNI pod filters [and they flow surprisingly well].


Flash from also writes: I did notice on your "Why re-jet a stock US bike" page you listed Part Number - 09420-40014 for #40 pilot jets. Could this possibly be a misprint? Maybe an old part number? I'm assuming you were referring to Suzuki Genuine Parts. The reason I asked is because I went to my local suzuki dealer with this number (you have 09420-40014 listed) and he said it did not exist. He told me the first 5 digits did not match up under the Suzuki Genuine Parts Catalog, but the last 5 digits did: part no. 09492-40014 What was funny is he told me the description just said "pilot jet". Since he knew I wanted size #40 he told me there was part no. 09492-40018 which had the description "pilot jet 40". I'm not sure if these were possibly bleeders because the pilot jets I ended up ordering (part no. 09492-40014), which were the ones which matched yours the closest, ended up being what I wanted: 1 Mikuni #40 non-bleeder pilot jet.


I suspect the number difference is due to ordering it either through the dealer or through or which would explain the differing first sequence of numbers but matching second set. fwiw, pablo-
Thanks to mjm and Piper5177 from