Small Engines (Lawn Mowers, etc.): Trimmer motor wont start, walbro, initial problem

Question
Thank you in advance for any assistance you can provide.

Item: Toro Trimmer Model # 51974

Initial problem: trimmer would start and idle, but when applying throttle it would stall out.

1.  Was told it may be the carburetor.  Carburetor was cleaned and repaired using a Walbro k10-wyc  repair kit for a Walbro WYC-7-1 Carburetor.

2.  Replaced carburetor and started trimmer and applied throttle but it started to gurgle, wouldn't stay running, had grey smoke wisping out of the muffler after it shut down, had fuel coming out of the air filter, and made a popping noise after shut down.  

3. Re-cleaned carburetor and checked all connections and screws etc.  Reassembled trimmer but then trimmer starter cable was very difficult to pull.  Also a large amount of fuel poured out of various parts of the engine housing.

4. Removed spark plug and pulled cable a few times and removed all the fuel that would come out.  Still looked a little wet inside.  

5.  Reassembled and tried to start using starting fluid but now it won't start at all.

I have limited experience in small engine repair and may have reached the point where I need to call in the Calvary. Any advice you could offer would be most appreciated!

Answer
Have you checked the engines compression?

Will the engine start and run with the muffler removed?

Did you read the Walbro service manual to make sure you have the carburetor properly set?

http://wem.walbro.com/distributors/servicemanuals/

Let me know if it runs with the muffler removed.

Eric