I got another idea about the stalling engine after a while of normal running..#
I have a 2000W AC generator with a 4-stroke engine in case electricity is dead for longer. This engine would not start. Finally, I found out that enough fuel would not reach the carburator if the fuel is very low in the tank, though a fuel surface is still visible. After filling more fuel, it would start and run ok.
When trying to repair the Victa mower I usually keep only a little fuel in the tank in case I have to empty it. When looking into the tank, a vertical plastic blade is visible on the bottom, and the fuel is below the upper rim of that plastic part. I looked in the manual to see whether it instructs about filling a minimum fuel amount to cover this vertical part in the tank - nothing mentioned anything about it.
I disassembled the carburetor again. When I detached the fuel line from it, fuel would drip from the line and the carburetor. I disassembled the carburetor, floater + needle, jet etc and blew everything through with pressurized air. Reassembled, filled the tank almost to the top with fuel and now it works as before.
I do not know what helped, but I can live with that uncertainty as long as the mower works again.....
I would have been a bit disappointed if I had to abandon it after only 31 years....
