Small Engines (Lawn Mowers, etc.): Toro Snow Thrower spitting gas/oil, carburator repair, adjustment screw

Question
I was just given a Toro S200 snow thrower that is very old. It has a two-stroke Tecumseh engine. It was not priming right so I put a carburator repair kit in it. Actually, I only put the lower part of the kit in (diaphragm, gasket, inlet needle, seat, and spring). It primes and starts real well now. But a lot of unburned gas/oil mixture is coming out the exhaust and getting all over the driveway. I have adjusted the right screw ("Main" adjustment screw according to a parts diagram) and it just changes the idle speed as far as I can tell. I haven't tried the "Idle" adjustment screw as I didn't want these to get too far out of whack. How do I properly adjust these two screws? And will that reduce the ammount of unburned fuel coming out the exhaust? Or do I have another problem causing this?

Thanks

Answer
Hi Steve,

These are the things I would look at:
Try adjusting the carb.  There usually are 3 screws.  The high speed mixture screw is initially set at 1&1/2 turns out.  The low speed mixture screw is set at 3/4 turn out.  The idle screw (Which stops the throttle from closing completely) is set to give a good idle.  
The next area to check would be the lever for the needle, located under the diaphram.  Usually it is set to be flush with the top of the carb body.
Your gas/oil ratio should be 40:1.  Too much oil could result in unburned oil coming out of the exhaust.

Let me know how you make out.
Michael