Well I have taken the top end off( 1hr 15mins a new record) and found nothing,nada,nought. No up down or twist on the conrods,no movement up down or sideways on the crank. The only issues were the inlet valve clearances had closed up a little, a little play in and out on the belt drive pulley(prob cork washer),soldered joints on the oil feed pipes(not that old) loose and leaky rockerbox gaskets. When turning the engine over with the kickstart some rumbley(difficult to explain) noises/feeling from the gearbox- bearings??-very odd. still I can clean up the top end retime the engine with the head off and regasket. Any suggestions people.
Andy