I have a craftsman 5/22 blower. I installed a new plug in the fall. I filled up the gas tank, started it and started to plow, but it keeps stalling out when rotor and wheels are activated. It runs good when sitting at an idle. Why?

I run a lawnmowing, weedeating business, mowing for other people during mowing season. I have 2 riding mowers, and 3 weedeaters, plus a good chainsaw I use in the winter(now) for cutting firewood.
This might be your problem. Do you use Regular Unleaded gas in your snowblower?
If so, the carburator might be "gobbed off" with residue left over from the regular gas. Regular gas is not the same quality as it was 15 years ago... it's much, much worse now for small engines. My small engine repairperson told me to only use Premium gas. I started using it 3 yrs ago, and have NOT had one problem, other than normal things happening; but not the engine or carburators. If your carburator is clogged up, then it cannot supply the gas needed when required by the engine to use more when you rev up the engine. I wish you the best. You might try a little carburator cleaner squirted into the air intake, under the air filter, but don't use too much.
Before he told me about the Regular gas, I was having problems about every 3 months!

Aside from what was mentioned above, are you sure the augers are turning? I have a Yard Machines snow blower and it has shear pins on the augers. If one of the pins snaps and both augers don't turn, it will stall out if I try to do any worthwhile amount of snow.