Oh i know the answer to this one :D
these super(joking) little bikes have valves that are made of chocolate or just very soft metal and the valve clearances tighten up as the metal wears away from the valve opening and closing.so the very small clearance it has left totally goes when it warms up and then it stops and you have to wit for it to cool down again before it will restart.
so the answer is to take the seat bucket ouit,then the small panel behind your ankles as you sit on the bike then undo the 4 8mm headed bolts that hold the rocker cover on and the two small 8mm bolts that hold the recirculation pipe on the head,then carefully turn the engine over until its on top dead centre this will be on a colpression stroke so it will have a slightr resistance to the lever when the engine is cold of course,then line the two markks on the cam pulley with the heads flat surface and then check the valave clearances ,there will be none i expect especially on the exhaust (bottom one)then get a feeler guage and undo the lock nut on the tappet adjusters and set the clearances to .08mm on the exhaust and .0 on the inlet out it all back together and it will be fine. simples
adam b doc
July 2012
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix motorcycles.