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.......
 
 
 
 
 

Hi Mike
 
hard to say if it's running out of gas or just losing spark.
It shuts down pretty quickly.  
It's not "chugging" for 5-10 seconds before it shuts down.
It takes like 3-4 seconds to shut down.
Some other guys are telling me it could be the gas cap (not venting) and I suppose that's true...but....it's a pretty large tank and I remove the gas cap before starting it again and there's plenty of air in there.  Hard to believe that using up a 1/2 ounce of fuel will draw enough vacuum to prevent gravity flow of gas to the carb.
 
some other guys were saying maybe the ignition is shutting down.  Like maybe the coil is losing ground or continuity to the plug wire or something like that.
 
I think I'll run it with the gas cap "loose" next time and if she still shuts down then I'm going to troubleshoot the ignition system and grounding etc......
 
Lee

Plus one on the tank cap.  
 
Also plus one on the coil. The coil however, over time will get worse and worse (if not quit immediately),
so I'm leaning towards tank venting.
 
if the cap isn't the issue have a spare spark plug handy.
When it quits, plug in the known good plug, ground and visually check for spark.
 
I've had, on rare occasions, the plug light off OUTSIDE the cylinder.  Install, NO START.  ??
Install another known plug in the head, cranked right up....
 
 
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