I have a 2001 400ex and just bought a new mooseracing O-ring chain. I put it on and now I am having problems adjusting it. Yeah, i know loosen the allen head bolts and pull the adjuster back with a screw driver, but that doesnt seem to be working. I can move it either way and it will not come even close to making the chain tight enough... and yes the chain is the right size. does anybody have any idea whats going on or maybe im over looking something???... thanks

 

I'm not sure as to the exact problem your having? If you loosen the allen head bolts and can you rotate the chain adjuster back?

 

Did you actually count the number of rollers and/or links, and compare it to the old chain? Are the sprockets stock? Someone may have changed the original back sprocket to a smaller tooth count.