Small Engines (Lawn Mowers, etc.): tecumseh wont start, but backfires, blown head gasket, carbureter

Question
I have a 5hp Tecumseh motor on a go-cart and it won't start but backfires. I have checked the magneto,flywheel key and the carbureter.  please advise of anything else that could be wrong with it.

Answer
 Hello Lucas:

 Check for a Blown Head Gasket. Check the Valve Clearance. Here are a Couple of Addys I give All the Tecumseh Owners. I have been told They are Very Helpful. 1- http://www.cpdonline.com/692509.pdf 2- http://www.tecumsehpower.com/CustomerService/BSI.pdf Send me the Model Numbers Off the Engine, Please. With these I can Locate the Proper manual and Better Assist you. Thanks.

 Respectfully

 John