Small Engines (Lawn Mowers, etc.): 2-cycle wont run, exhaust port, fuel flow

Question
Thanks for the help, the problem has just started this season, the unit is about 6 yrs old.  
Using starting fluid is the only way to start it.  Again it will run for a while but usually as the throttle is moved from choke to fast it dies out after a minute.
The fuel is fresh. Is there a fuel filter on these small engines?
Do you think a carb rebuild kit is necessary? I read carbon build-up in the muffler may lead to poor performance too.... Have you ever come across that?

Thanks


Followup To
Question -
I have a Craftsman 22cc gas blower (model 358.797910) that starts but will not continue to run, usually dies after a minute.  I changed the plug, cleaned the air filter, and adjusted the carb......didn't help.
Also do you have any suggestions on getting it apart if I need to get at the carb, muffler, etc.  

Thanks
Answer -
Hi Jim,

You will need to remove any covers or panels to access the inside.  They should snap off or unbolt. First, try squirting fuel or starting fluid into the carb opening to see if you can keep it running.  That will narrow down the problem to a lack of fuel flow.  Did the power slowly start to get weaker over time or is this a sudden issue?

Let me know how you make out,
Michael

Answer
Hi Jim,

There is a filter on the end of the fuel pick-up line, inside the tank.  Fish it out with a wire, pull the filter off and blow it out with compressed air.  If that doesn't help you will probably need to remove, disassemble and clean the carb or add a rebuilt kit.  There may be dirt, debris or gummed fuel inside.  
Carbon build up inside the muffler, muffler spark screen or exhaust port will, over time, cause an increasing loss of power, ending up in a no-run condition.  A port can be carefully scraped clean.  Screens and mufflers are cleaned of carbon by heating with a porpane torch.

Keep me posted and
Good Luck,
Michael