Small Engines (Lawn Mowers, etc.): Weedeater not starting, carburettor, fuel cap

Question
I serviced the carburettor, changed the ring and tried to start but it wouldn't.  I was wondering if the ring was installed wrong.  I am getting good compression yet the machine wouldn't start.  How is the correct way to install the pisaton ring

Answer
On most trimmer engines, there is a pin going through the ring land.  The ring has a corosponding groove in it.  It has to align up with the pun.  

If there is a top and bottom to the ring it will  have a dimple on it or say top on it.  

When you say you serviced the carb did you clean the entire fuel system.  In the system is the fuel cap vent, fuel tank, in-tank filter fuel line and a small screen in the top side of the carb body.

If you installed a carb kit besure the inlet needle is adjusted per the manufacturers requirement.  If you have not installed the kit so so.

Hope this helps