Carb Jetting ~ Suzuki GS500

Some of the good people on the GSTwins Forum have helped us out and told us how they jetted / rejetted their carbs (carburetors), based on different air filter and exhaust pipe configurations.

But first, lets pay some bills:

Name Year  Exhaust   Air Filter  Pilot Mid Main Wash
STOCK1USA 1989 Stock Stock 37.5 0 122.5 0 0 from GSTwins Wiki
STOCK1 1989 Stock Stock 40 0 122.5 0 0 from GSTwins Wiki
mrhawx95 1998 Stock Stock 40 0 127.5 2 3 runs far better, little on the rich side idle still not 100%
boxin 1998 Stock Stock 42.5 0 127 3 3
nakedgs 1992 Stock Lunch 40 0 132.5 2 3 Runs great, probably a tad rich at idle.
aero_b 2000 Stock Lunch 40 0 142 1 2.75 Too rich, but safer than 132.5 (too lean & backfiring). Will go down and re-post settings
mrhawx95 1998 Slip Stock 40 0 127.5 2 3.5 Near perfect, pulls great now and idles good. Using delkevic slipon.
ineedanap 1990 Slip Lunch 40 0 134 0 2.5 DYNOJET KIT. Didn`t drill slides. Needles on 3rd clip from top. Runs great
jeremy_nash 1995 Slip Lunch 40 0 142.5 0 0 jets only, airscrew setting was good, so I didnt mess with it
Paulcet 1997 Slip Lunch 40 0 142.5 2 2.75 Runs great!
psyber_0ptix 1991 Slip Lunch 40 0 150 2 3 +79ft elevation.Runs a tad rich, might try taking out a washer and reducing main to 147.5
STOCK2 2001 Stock Stock 17.5 60 127.5 0 0 from GSTwins Wiki
STOCK3 2003 Stock Stock 17.5 60 130 0 0 from GSTwins Wiki
DanUK 2004 Stock Stock 17.5 60 130 2 3 3rd clip position, runs great
scooky 2009 Stock Stock 20 60 132.5 1 3 oring washer Happy hot cold and better low rpm response
respite 2007 Stock Drop 20 60 132.5 2 3 far better than stock.
radodrill 2009 Stock Drop 20 60 142.5 1 2.5 No restrictor on K&N filter
BeerGarage 2001 Stock Lunch 20 62.5 142.5 1 3
sikiriki 2002 Stock Lunch 22.5 65 142.5 0 3.5 satisfied, on the lean side but ok.
kd7011 2007 Slip Drop 20 62.5 142.5 0 3 Better
mitch 2003 Slip Lunch 20 60 142.5 2 3 bike may be a bit lean, will rejet to 20/65/145 or 147. Does not run well cold (needs floats done)
patrick curley 2002 Slip Lunch 20 62.5 150 2 3
Unsane 2004 Slip Lunch 20 65 145 0 3 Bit cranky when cold but much better warmed up - midrange & top end punch improved
spray____ 2006 Slip Lunch 20 65 147.5 0 0 close enough for me for now
drewbytes 2008 Full Pods 20 62.5 147.5 0 3 increased idle to approx 1000 cold, 1400-1500 hot
Black and silver 2007 Full Lunch 20 62.5 155 1 3.75 12.5:1 AFR
galahs 2005 Full Lunch 20 65 145 0 0 Jets only rest are stock settings but increased idle spped a touch
Punkal 2006 Full Lunch 22.5 65 147.5 0 3 Bike is rich rejetting to 22.5/62/5/142.5


Stock = factory exhaust
Slip = slip on exhaust can over stock header pipe.
Full = full headers and pipe performance exhaust system.

Air Filter:
Stock: factory air filter and box.
Drop: K&N type air filter replacement slipped into the stock air box.
Pods: K&N type cone air filter pods installed one onto each carb.
Lunch: Large K&N type air filter installed over both carbs.

Pilot: pilot jet size
Mid: mid range jet size (GS500 carb changed from 2 jets to 3 jets in 2001)
Main: main jet size

Washers: small washers installed under main jet needle to raise needle (two washers are roughly equivalent to one clip position on a jet kit replacement needle).

Air Screw: number of turns out from gently seated on the air adjustment screw. "0" turns out in the Air Screw column above means unknown or not modified. If your get to 0 turns you need a smaller main jet.

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