The KMX 125 and 200 do not have shims in the powervalve and they are not adjustable . To raise the output remove the collar from inside the exhaust where it joins the barrel or buy and aftermarket exhaust. This does not apply to the 200 as it is not restricted. The 125 will probably put out no more than about 24 horses after this if you are lucky. They are fast but don't be fooled they will turn into some kind of rocket.