Small Engines (Lawn Mowers, etc.): Stalling Lawn Mower, fuel flow, lawn mower

Question
My lawn mower suddenly started stalling every time I turn the throttle up.  With a low speed setting, I was able to mow for a solid 20 min.  Each time I turned the throttle up, though, it died again.  When I finished my front yard, I let the mower run with no additional load (on my driveway).  It ran fine until I turned up the throttle to about 3/4.  It died in less than a minute (but not right away).  Sounds similar to a mower running out of gas.

Any idea what might be wrong?  Do you recommend a particular troubleshooting strategy?

Answer
Hi Mario,

First, make sure that the air filter is clean.
I suspect a lack of fuel flow to the engine.  You could try opening the high speed mixture screw a little.  If no better, you will need to remove the carb, disassemble it, clean all the small internal openings and blow it out with compressed air.   Probe each and every hole with a small wire.   A carb rebuild kit wouldn't hurt either.  

Let me know how you make out.
Michael