Small Engines (Lawn Mowers, etc.): B&H 15.5 OHC Riding Mower Enginge, water in the fuel, fuel lines

Question
I left my riding mower outside over the winter. I live in Atlanta and the mower was covered.  When I went to start it up in the spring, no luck. It wouldn't turn over.  I replaced plug, fuel lines, fuel filter and sprayed gumout in the carb. The engine would startup and run if I sprayed starter into the carb but would die when that burned off. I found that the cellenoid piston was not dropping so I replaced the cellenoid.  Now, when the engine is cold and the carb is dry, I can get it running for about 3-5 mins.  After this time it will only keep running if I choke the carb.  I tried adjusting the mixture thinking that the carb was being flooded but no combination of mixture or choke will keep it running consistently.  I am pissed off and don't know what else I can try.  The mower is only 3 years old.  Can anyone help? Thanks. JDG

Answer
Hi John,

If it starts and you can keep it running by adding fuel, then the carb most likely has dirt, debris or gummed fuel inside.   
You will need to remove the carb, disassemble it, clean all the small internal openings and blow it out with compressed air.   Probe each and every hole with a small wire.   Adding a carb rebuild kit wouldn't hurt either.  
Also check for water in the fuel.  

Let me know how you make out.
Michael