A friend of mine just bought an '07 YZ250F from a guy and when sitting on the bike the rear shock seems to bottom out after about 3-4" of travel. There is definitely a hard stop. We tried setting the sag, rebound and damping back the the factory settings. The sag was way off. This helped a little, but it is still only compressing about 4". What could be going on with it? Any ideas? We really need the help. Thanks.