Need stock rear sprocket size

[mattn03]

What should be the stock rear sprocket size be on a 2005 400EX? I thought it was 38T, so I just bought a PD 38T sprocket. Lo and behold, when I pulled off the original sprocket, it was stamped 39T. I bought the ATV used, so the original owner may have swapped sprockets, but he didn't mention that when I bought it.

I'm going to be running 23" fronts/22" rear tires and just bought a 13T front sprocket to gear it down. Can I go ahead and use the 38T that I just bought or return it for a 39T?

[drew416ex]

39t, I think 2004 and below are 38. Mines a 2001 with 38

[drew416ex]

You can use the 38 but it will gear it up just a notch, but not much since its on the rear.

[mattn03]

mmm, I hate to loose any low end since I'm only trial riding, so I might just try to swap it out for a 39T. Is Rocky Mountain good about returns?

[jrafter]

i put a 38 on mine and it helped 1 gear out for buttin around

[08400EX]

Originally posted by mattn03
Is Rocky Mountain good about returns?

Doesn't get any better....well maybe if they sent someone to your house to swap them out in person :-)