Hello people, i'v e got a 05 DTX. I've heard people talk about the power valve where the exhaust meets the barrel. What do you do to it? And will that work on my 05? Not really sure what to do. Any help would be appreciated. Cheers

The powervalve sits inside the exhaust port. It has a section cut out to meet the shape of the exhuast port. In simple terms it turns in the port to make the hole where the petrol and air can escape smaller, so you get more of a bang and therefore more power. On a 2005 model it should be fitted and operational. They are sometimes pinned so that they dont operate as a restriction. All the info you should need if this is the case, will be on this page.

http://www.dtr125.net/tuningf.htm

If it is not already, click 00-03 models. But as that suggests, your model should not be restricted in this way.