Ok so I have a 2004 dvx400 and I was riding and turned it off to take a break. When I got back on and started riding i opened throttle all the way and it would only rev a little bit like the rev limiter was really low. If anyone has any idea why it’s doing this please let me know.

 

Might be in Limp mod. Some ATV will do that when their is something wrong. Usually won't let you open the Throttle or come out of first gear as well.