So there he was riding it along a little 50 cc 2 stroke and then it cut out.
He has , checked for fuel, changed fuel, changed spark plug checked ht lead , dismantled and cleaned all carb, in vain ordered and fitted new piston and barrel. He knows there is a spark, he knows the fuel is ok, knows there is compression, a mechanic over the way is also baffled. Over to you guys in desperation.
Have you full fuel In flow? could there be a blockage in the line? leave the feed line off whilst pumping the fuel through. Is there plenty of fuel?, If you he done all you have stated I would go with the Spark.
TWR sorry getting back to you so late.....the oil belt had snapped, the engine had seized and there was no compression ( despite himself swearing there was). A new belt , piston and rings, and away he went . Thanks for your answer.