Honda CRF 80 topping out at 25mph?

Hi, I have a 2004 Honda CRF80 who's top speed is supposed to be around 50+ MPH. Well our CRF for some reason is topping out at only 25. The engine and exhaust seem like their revving to high to early and the sound is a lot higher just cruising in each gear. The bike runs just fine but I know it should be going a lot faster than it is. I would really appreciate any help that I can get.

Most likely needs a new top-end, new rings likely but a piston/bore is quite possible.
Little engines work their @ss off supplying power, your's is 8 years old so you might wish to have a look-see inside.

Make sure your air filter is clean and properly oiled.

Are you sure there's no throttle restriction?

Is the throttle cable pulling to its maximum?