A lot of the push mowers down here use PVC fuel line
Goes hard eventually due to heat so pulls away from the barbs & leaks if it does not crack first
To be honest Victa do say to replace it at every 5 years service but most leave it till it is rock hard
FWIW the late models use pneumatic governor & pneumatic decompressor so all of the mower uses the same PVC lines on a 5 year replacement