maybe breather pipe isnt the right word... its a black rubber pipe abput 8mm dia that runs vertically from the tank down behind the crank case and stops just behind the back brake pedal.
i'll try and get some pics tomorrow of the white open topped pipe next to the air box tomorrow. and see if the breather next to the filler cap is blocked..
other than that i might try and fix it with a box of matches..
k