problem is, that on the SR 41 (and 42 - I'm not quite sure?) with a worn o-ring in the floating-valve the petrol gets into the engine oil as there is no overflow from the carb to the outside. The level of fuel rises until it reaches the inlet, passes the valves and the piston-rings and mixes with the oil. So always close the petcock on the early models!!!
Kind regards, Bambi
'Find me kindness, find me beauty, find me truth ...'
(Dreamtheater, Learning to live)