Started my 5hp craftsman 5 year old snow blower at beginning of season. It puttered when choke was off, so I cleaned the carb. Bowl and replaced the o-ring. Still puttered. When under load, it seemed as though she would stall. Replaced three week old gas and put stabilizer in it... still puttering.

She runs like a dream when in the first choke position (the one just before the off position), while idling and under load.

How can I get her to run with choke off and not putter or stall when under load?

Thanks for your advice!

Sounds to me like the fuel circuit(s) in the carburetor need to be cleaned out. You should use carburetor cleaner and an air-hose is a MUST for blowing out the small drilled orifices and passageways.

I have a bottle of fuel injector/carb. Cleaner, it that what you are talking about? If so, how much should I use? And how much time should I give it to see results?

Where exactly are the "drilled orifices and passageways" you mentioned? Can I see them from the outside, or do I need to open up the carb. When I blow them out, how do I know when I have done enough?
What things should I be aware of while I'm doing this so I do not worsen the problem?

Thanks for all your help!

Where are the "drilled orifices and passageways" you are talking about? Are they on the bowl nut? Anywhere else? I have a bottle of fuel injection/carb cleaner, is this what you are talking about? If so, do I put 1 oz into a full tank? Thanks!

I have a bottle of fuel injector/carb. Cleaner, it that what you are talking about? If so, how much should I use? And how much time should I give it to see results?

Where exactly are the "drilled orifices and passageways" you mentioned? Can I see them from the outside, or do I need to open up the carb. When I blow them out, how do I know when I have done enough?
What things should I be aware of while I'm doing this so I do not worsen the problem?

Sounds like you have cleaner you add to the tank and then run the snow blower, drive the car, etc. and allow the stuff to do it's job. You're beyond that, your carb. Needs to be manually cleaned out. Not sure what engine (probably a Tecumseh)or Carburetor you have but I'm betting it's a pretty basic carburetor. In a nut-shell, without going into a lot of detail, you need to remove the carb. From the engine, remove the float bowl, float, needle valve and seat. That will expose some orifices, i.e. drilled ports. Also, looking in the throat of the carburetor I'm sure you'll see some small holes. You need to get some spray carburetor cleaner with a straw applicator and spray cleaner in those orifices (holes). Then you need to use an air hose and blow air through those holes best you can... every one you see. Often times you can feel the air coming out another hole, assuring you that passage is clear. As you blow the air, move you finger around over the holes to see if you can find where the air is exiting that passage. If you've never disassembled a carburetor it's best to do it with an experienced person guiding you for the first time. Good luck!

Can't thank you enough for you advice!! I'll take the good luck you passed along, too :-)