JT lists the stock sprocket for the 1994-2002 GS500E and 2004-2009 GS500F as the JTF 516, available in 13, 14, 15 or 16 teeth.

The stock sprocket for the 1989-1993 GS500E is listed as the JTF 565.

Apparently they don't make a sprocket for the 2003 

The GS500 Wiki appears to show the JTF 513, available in 13, 14, 15, 16, 17 or 18 teeth as an alternative sprocket for the GS500 (http://wiki.gstwins.com/index.php?n=Upgrades.Sprocket) although it has no flange, like the JTF 565, so I presume it is not compatible with my 2007 F model.

The AFAM and Motorcycle Superstore links on the wiki are broken, and Bike Bandit says AFAM does not make an 18tooth front sprocket like the one quertydude bought from someplace he doesn't remember anyway 

Whereto now 

I don't have any advice for you on where to buy the sprocket - but they didn't make the GS in 2003 (or at least, they didn't import it to the States. I don't remember which it is). Might explain the year discrepancy.

The 2003 sprockets are the same as all GS500/E/F sprockets from 94 to present.  No 2003 model GS's were sold in the US but they were sold on many other world markets.

http://www.jtsprockets.com/52.0.html?&L=0&sel_uid=1635&p=

MC Superstore shows the pricey AFAM 18T front sprocket available:

http://www.motorcycle-superstore.com/1/5/85/10051/20513/PITEM/AFAM-520-Front-Countershaft-Sprocket-2002-Suzuki-GS500E-Parts.aspx

I usually check bikebandit parts diagrams for a 2004, no websites list anything for a 2003

mines a canadian 2003

sprocket design did change in 04. an 04+ sprocket wont physically fit an early model due to the width of the shoulder. an early sprocket will fit an 04+ bike but it will have slop due to the early ones having no shoulder.

All 1994 and later up thru 2009 use the same front sprocket with the shoulder, it was the 89-93 that had no shoulder. 

Quote from: gsJack on April 24, 2010, 02:49:19 PM
All 1994 and later up thru 2009 use the same front sprocket with the shoulder, it was the 89-93 that had no shoulder. 

I stand corrected, 94 up have shoulder. good that a more knowledgeable person saw that.

No confusion on the shoulder/no-shoulder issue; thanks to gsJack for a link that actually worked 

Quote from: black and silver twin on April 24, 2010, 02:08:35 PM
sprocket design did change in 04. an 04+ sprocket wont physically fit an early model due to the width of the shoulder. an early sprocket will fit an 04+ bike but it will have slop due to the early ones having no shoulder.

Yeah I ran into that problem when I ordered a smaller sprocket; they sent me the wrong one. Rather than send it back and wait another forever, I ended up putting a washer or something in there to keep it from slopping around I think.

Quote from: SAFE-T on April 23, 2010, 07:23:54 PMThe GS500 Wiki appears to show the JTF 513, available in 13, 14, 15, 16, 17 or 18 teeth as an alternative sprocket for the GS500 (http://wiki.gstwins.com/index.php?n=Upgrades.Sprocket) although it has no flange, like the JTF 565, so I presume it is not compatible with my 2007 F model.

Ok, so the JTF513 is for a 530 chain, so no go with the OEM rear sprocket and a 520 chain 

Now looking for a Canadian retailer as Motorcycle SuperStore wants $39.99 for shipping. Yes, that is correct - 40 bux to ship a front sprocket 

It's the JTF 512 that also fits the 94 and later GS500/E/F if you want a 17 T but no 18T available.  Same width shoulder as the JTF516 standard sprocket, shoulder is larger dia but fits and has been used by some here.