Small Engines (Lawn Mowers, etc.): Tecumshe carb, throttle valves, needle valve

Question
I have a 10hp horizontal Tecumshe engine.
The engine is about 10 yrs old (Model # MM100-159022D) but has less than 10 hours of use on it. The engine has been sitting for about 9.9 years.
The carb had hard varnish in it, but I was able to clean it out.
I was able to start the engine which ran at high speed but would not idle. After another good cleaning it now will idle and run at high speed.
Here is the problem: When accelerating from idle to high speed quickly, the engine will die. If accelerating slowly, it works fine.
I read somewhere that if you hold the choke and throttle valves, (with the float and needle valve removed)the carb should rattle when shaken. (emulsion tube?) is this true? My carb won't rattle. What does the emulsion tube do?
Do you have any suggestions?

Answer
Hi John,

I don't know what the emulsion tube does or if it should rattle.  
The problem sounds like a lack of fuel flow to the engine.  Make sure you have a good flow from the tank, then I would suggest disassembling the carb again and checking every opening and movement.  One small hole that is clogged and missed will cause problems.  Use a small wire to probe and clear.  Check the float for being fuel logged.  I have had to remove and reclean a carb several times before getting it right.
If that doesn't help, check the compression and valves or replace the entire carb.

Let me know how you make out.
Michael