Hello! I have problem with an old engine too. I cannot start it. Fuel is drown to the carb and if I remove the plug it is also wet. I replaced the spark plug and checked for a spark but I only saw sparks a couple of times. I assuming that the ignition has problem (It is the old style, not electronic, it is like Zenoah 38). If the ignition coil has problem how can I fix it?