Small Engines (Lawn Mowers, etc.): 49cc engine will not start after it is warm, compression gauge, adjustment screw

Question
Yes it does have spark.  I have even put a new plug in, then after it has run and is warm still will not start, pulled the plug and checked for spark and it does have a good spark.
Thank for the quick reply

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Followup To
Question -
I have a 49cc engine in a mini motorcycle.  when it is cold it will start right away using the electric starter.  After it has been riden for a while and warmed up (running good), if you turn it off it will not start again for several hours.  The carb. only has one adjustment screw and one for the idle
Answer -
Have you tried replacing the spark plug?  It may be fouled. We find bad plugs in 2 cycle engine very often and the bad plugs act exactly as you described.

The next time you it refuses to start remove the spark plug and check for spark.

Let me know if it has spark when warm.
Eric

Answer
These problems are always difficult to trouble-shoot.

If you have good spark and the plug is good then there maybe a compression or fuel problem.

Do you have a compression gauge?  Is the air filter easy to remove?  How may hours are on the engine...how old is it?

Eric