'06 EC300 ajs front wheel spacers
 

Where can I get replacements? Mine have serious grooves worn in from the bearing seals, but I can't find any reference for replacement parts.

If you have a 20mm front axle, then these are probably the part numbers:
BC250018018
BC250018019

(these were correct for my AJP hub with 20mm axle).
I got mine from Greenland MX, but any GG parts place should be able to get them.

http://www.greenlandmx.com/gas-gas-f...d-p-1-51-4712/

Thanks! I'll look for a parts house here in the US.

Where are you located?

Gofasters is in Minnesota and Gasserparts is in West Virginia for a parts source.

What forks do you have?

checkpointoff-road.com is the shizz.

I checked the Gofasters website, and their on-line parts finder only listed DC-enduro models for 2006 (what are those?), so I had to go down to 2004 to find an EC300 (mine is an '06). Hope it's the same size.

So the listing shows part #BC250418019 and Qty (2) for front wheel "bushings".

My axle is 24.8 mm (as close as I can measure). Can anyone confirm that these are the parts that the front wheel seals seal against, and that 2004 will fit my 2006?

You also can find the parts diagrams right from GasGas's web site.
http://www.gasgasmotos.es/en/manuals/3.html
Go to the exploded listing of the correct year. I hope this helps.

Definitely DON'T order the ones I put earlier as you have a 25mm axle.

You mean DE? It stands for 'Dealer Edition', which is an EC with some extra bits added on by the dealer. You can read about that in the GasGas History thread in the general section if you want to understand the exact mods that were done.

Anyway, yes the part number BC250418019 is correct.