peugeot jetforce 125, loses power?

I had the exact same problem. On my bike it turned out to be the bypass valve. You can get one from here:
http://www.peugeotscooterspares.co.uk/spares/partImage.asp?GPN=ZUJ;:;8
It is really easy to replace, just take the tub out from under your seatHere is a free download of the jetforce technical manual to help you.
http://scootercommunity.com.au/files/folders/6402/download.aspx
good luck

neil
March 2010