Walked into the mower shop today, and guess what was being picked up by a customer - a victa super catcher with 550ex.
Asked the mower's owner - same symptoms - black smoke out of exhaust (rich mix), revs and stops, etc.
All that was billed for was air filter, pre filter, plug, new oil (she said her son over filled it). Labour was only the regular service labour, so doesn't seem as though tear down was required.
Wonder if its fixed.
Are you sure its fuel and not oil spitting back through the carby, just in case something is up with the crankcase vent system. If the oil clogs the paper filter, no air flow and no revs/running as thecarbymaster said.
Speedy, could you post a couple more images of different angles of the carby?
