Small Engines (Lawn Mowers, etc.): Sears riding lawn mower quits after getting hot, sears riding lawn mower, riding lawn mower

Question
I have a neighbor who has a sears riding mower tat quits after about 2o minutes It acts like it running out of gas so i took the fuel line off at the carb. and not gas took the line off at the filter on the outlet side of filter no gas on the inlet side of filter has gas. it acts like it is vapor locking. I thought mayb the fuel cap vent plugged  so i took it off  no help. it a new filter and fuel line.  tank cleaned out. got any suggestions. thanks.

Answer
Try replacing the spark plug even though it sounds like the fuel cap may be causing the problem.

Does the fuel cap actually have a vent hole in it?  Many of the newer tanks vent via the threads in the cap but we have had trouble like you described.

What size engine does the mower have?
Let me know.
Eric