Is the primer bulb filling with gas. If not it may not be getting gas through the carb and requires a carb kit and cleaning. This should be done only by a repair man. If it's filling with gas, prime it at least 7 times, choke it on A (not C) it will pop and may start then go to B, prime it 2 more times then it will run, run it for about a half minute then go to C. Many people think C is choke. It IS NOT. A-B-C is the order of starting. On some it may be 1-2-3 which is the same order of starting.
Bob, August 2007