I worked my PV today.
Photo 1 is how I found that PV was on my DT125R. I understand that the position is closed
Photo 2. This is how the closed
PV was included in the pulley.
Photo 3. This is where I moved the PV in the pulley to open.
I'm happy to say that this has improved my motorcycle. The engine will now play more freely.
thank you for your advice.