I have a 99 crm250 with a bad carb. The cylinder inside the carb moves and therefore my throttle will often stick. I'm wondering if anyone knows where I can buy a used one or a rebuilt one online or if it's possible to fix it. Thanks

If it's a Mk3 then Thorpespeed have one -http://www.thorpespeedracing.co.uk/26.html

If an AR they are breaking an AR but don't have a carb listed . Otherwise eBay every now and then.

Not sure what you mean by 'movement'. You could get Leisure Trail to look at it before you condemn it .

Hi dedert,
If the slide 'wobbles' when its bottomed out in the carb body, it maybe possible to get the carb re-sleeved. This is quite common on classic bikes. Look up a carb specialist company. Im not sure if there's enough metal to do this on a modern carb, but it'd be cheaper than a new carb and if done, should take it back to as new fit.
Regards KK

Gidday,
Keihin Carbs can easily be sourced.
is it the original PE31mm?
Id so they don't make them no more, but from memory they do make a PJ series of an adaptable size and a PWK if you want a little bit better breathing. (If you go down this road, you need to do an full exhaust and reed valve change out to get the most out of it.) try http://www.keihin-us.com/am/" onclick="window.open(this.href);return false;
for more info.