Small Engines (Lawn Mowers, etc.): 5 HP Tecumseh Snowblower HSSK50, welsh plugs, screw assembly

Question
Hello Marc,
I have a snowblower with a Tecumseh 5 HP HSSK50 that has been stalling about 5 seconds after it starts. Starting is relatively easy but it just doesn't stay running. Priming it durung the stall usually brings it back up to speed momentarily but no way to use it this way. I pulled the carb and replaced just about everything and cleaned it well and now it won't even start. You had mentioned a passage in the stack that could be cleaned with an L shaped tag wire. Which passage is that? I'm unsure of what is meant by the stack. Is it the passage that the main mixture needle seats into? Any ideas on getting me started. Is it OK to test with starting fluid to see if the carb is still plugged? I do have spark.

Already replaced spark plug, float bowl, O ring, float, needle and seat, and main needle and bowl nut. Set float level as per Tecumseh manual at 11/64". Should I remove the choke and throttle plates? (don't think I have the tool to remount them)
What additional hole did you miss in your disassembly? Should I remove the welch plugs too? Is there anything under those plugs that could cause stalling? The carb is overall very clean. Engine has not had very much use.  

Answer
The stack in the carb is the part of the casting that protrudes into the float bowl and has the threads for the float bowl nut/high speed mixture screw assembly.  Up inside this stack is the hole I mentioned.  Don't disassemble the throttle or choke plates or remove any welsh plugs.  The orifices under the welsh plugs are large and rarely ever plug up.  There may also be a tiny hole in the side of the float bowl nut/high speed mixture screw assembly (in the brass part) that you need to make sure is clear with a piece of tag wire.  If you are really stumped, remove the carb and take it into a good shop...they can show you in two seconds where the problem holes are.  Hope this helps.