Tecumseh 8HP Snowblower Engine Shuts Off Every 3-5 Minutes - HELP HELP

I NEED HELP............
 
I have an old Snow King 8HP 2-stage snowblower with Tecumseh 8HP engine.
It shuts itself off every 3-5 minutes when I'm using it.  Very frustrating.
Not easy to start after that.  Needs to sit for a minute and I have to use electric starter for 10-15 seconds before it starts again
Plenty of gas in the tank.
It's been doing this for like 15 years !!!!!
When its running - it runs strong and throws heavy snow at high speed no problem - runs great.  Then it just shuts down!!
Years ago i took apart and cleaned and rebuilt the carb and it did not help.
Last year i bought a cheapy new carb on Amazon for like $30 and it works good - but the engine still shuts itself off every few minutes.
I thought it's the fuel line, but I checked the carb fuel bowl (by pushing up on the drain spring) and plenty of fuel comes out and keeps on coming.  Got 2-3 ounces no problem.  Appears to be no problem with fuel flow.
 
WHAT IS THE PROBLEM WITH THIS THING?   HELP.......