I have a sears walk behind mower. Honda engine. Just recently, it started to die out-as if it were out of gas, but there would be plenty in the tank. It will go from normal operation to a wavering sound, where you can tell it is having trouble staying running to the motor cutting out completely. I took a look at the fuel line and it seems to be OK. It is hooked right to the carb. There seems to be no fuel filter either. Is there some way to see if there is a blockage in the fuel line... maybe clean out the carb... I'm going to replace the spark plug today and see if that makes a difference. I changed the oil recently, but I do not see how that is related to this issue.

Your fuel inlet valve is probably sticking.

Drain the tank. Add some Seafoam carb cleaner and a small amount of gas. Start engine and let it run until it dies.

It may fix it without carb rebuilding.

For future reference:

1. Use high octane gas
2. Use fuel stabilizer such as Sta-bil in new gas near the end of the season.