Small Engines (Lawn Mowers, etc.): Toro Snowblower wont start, shortblock, pistion

Question
I just replace the shortblock on a 1997 6.5 Hps Toro Snowblower because the pistion was broken and cause the internal damage.Install everything back with all new gasket,spack plug. The unit start on the first try. Let it run for 30 secound then I shut it down. The next day I try to start it again and it won't start. When I replace the shortblock, I also clean the carb using the carb cleaner, repace the needle inside the carb too. Just don't know why it won't starting it now.

Answer
Did you torque the head?  Did you adjust the governor according to the shortblock instructions?  Is it an OHV engine?

Try replacing the spark plug...these fail more often than you think.

Let me know if a plug fixes the problem and let me know the answers to the questions.
Eric