loss of power

[adi1]

hello i have a 2011 honda pcx 125 the last 2 weeks when im driving at full throttle my bike gets to 100kph and the starts to slow down after 2 minutes to 90 and if im still at full throttle sometime even 80 i dont know whats the problem from what i saw online it can be the belt.
and when i accelerate there is no loss of power untill i hit 100 and then it starts to slow down.
how do i slove the problem ? thanks.

[easyrider]

fuel filter

[adi1]

fuel filter

Thanks but now I have a new problem. On my way home today the engine heat light turned on for a few seconds and I have coolant that I replaced 2 days ago with new coolant. If you can tell me what problem is it or it's just because I drove a lot?

[iceman]

fuel filter

thanks but now i have i new problem on my way home today the engine heat light turend for a few seconds on and i have coolent i replaced it 2 days ago with new coolent if you can tell me what problem is it or its just because i drove a lot

Check the coolant level for signs of a leak inc. the expansion tank. You may have introduced an air bubble / pocket if there is not a leak

[adi1]

fuel filter

thanks but now i have i new problem on my way home today the engine heat light turend for a few seconds on and i have coolent i replaced it 2 days ago with new coolent if you can tell me what problem is it or its just because i drove a lot

Check the coolant level for signs of a leak inc. the expansion tank. You may have introduced an air bubble / pocket if there is not a leak

how do i check/fix air buubles ? because there is no leak i fixed it 3 days ago and i check today and no leak