Originally Posted by Pleiades

The required emulator size is the same for all three XT models and several other Yamahas with 43mm forks. As the XT isn�t imported into the US, you�ll need to either search for the product by part number, or just enter TDM900 in the bike search and the correct emulator part will be listed.

Racetech

Part number: FEGV S4301 (TDM900 = XT660)

36.0mm/29.2mm/17.5mm

http://racetech.com/ProductSearch/2/Yamaha/TDM900/2002-09

Teknik

Part number: 25-051-07 (XT660R/X/Z)

36.0mm x 29.2mm x 17.0mm

http://www.teknikmotorsport.com.au/Browse-Parts/V4S-Valve-Road/Road-Travel-Control-Valve-Fork-Kit-36-0mm-V4s-Road.html#

There are also emulators available from Ricor in the US too, but I haven't looked into these.

Here's a useful sizing guide for emulator fitment from Racetech website:

http://racetech.com/html_files/EMULATOR_FITTING.html

FYI � The XTs have cupped top damping rods.

Note: The Racetech instructions tell you to drill the existing four damping rod holes out to 6mm and add two additional 6mm holes, although subsequently I�ve found out that apparently these emulators work just as effectively by drilling out the four existing holes out to 8mm. Basically all you need to achieve is to make the holes big enough to prevent any damping effect coming from the original damping rod as the emulator will do all the work once fitted.