Small Engine Gas Cap

I went to use my garden tiller this morning.. its a Husqvarna 900??
Anyway.. it started for about 10 seconds & died.. acted like it ran out of fuel..
I knew it was full so I went straight into diagnosis mode..
I pulled the fuel line to the carb & nothing came out.. I loosened the fuel cap & she poured out..
I didn't know small gas engine caps were vented?? I'm over 50 years old & this is news to me!!!
It was 90* outside & didn't go any further w/any fixes, just left it loose & tilled the weeds under..
I'll get back to it in the morning.. but like I said.. this is news to me.. I had no idea..

Yep, all are vented, or gas wouldn't flow. Check the cap, itself. sometimes insects can clog the vent, by closing a hole or holes. Some cavity nesters dab mud over small holes, after depositing a victim, with an egg laid on it, Hole spiders, I call 'em. If it ain't hole spiders, it may just be debris, try taking the line to the tank off the bottom of the tank, hook it to an air line, and pressurize the tank, with the cap on. Of course, tank should be empty..

YUP, I see it now.. its a cap inside a cap.. To early to turn on the compressor..or I'll have to live w/ a grouch the rest of the day.. she needs her rest..

A lot of Honda inverter generators have a t-bar type valve handle on the cap that is opened or closed. Close it and you can throw it in the trunk of your car upside down and not smell the fumes. Well sometimes I get calls saying generator runs half an hour and then dies. Tell them about the valve and usually never hear back....

Had a chinese generator at hunting camp and it would run half hour and quit had to use a pipe wrench to get the cap off,left it a little loose and it would run for the whole tank.Might add that it was brand new.

some caps are vented . Ive seen tanks with vents as well .