when it opens you can lean back lift your legs up and go ahhhhh like it has 1million HP.
You cant make a Powervalve hit harder, The closest thing is either pin it open so you have full power all the time or you can tune up the engine or get a Big bore kit from athena. I heard the DT200 Barrel fits straight onto the dt125 engine but you will need the 200 piston and crank and probly more stuff
