If you are experiencing ignition timing issues, this is most often due to a sheared flywheel key. Breaker point systems: used on engines made before 1980, these systems use a mechanical switch instead of a transistor to close the electrical circuit used to produce a spark.Solid-state systems: the more modern option, these systems use a tiny transistor in the coil or armature to close the electrical circuit that travels through the spark plug lead to the spark plug(s).Once the engine is running, the flywheel keeps rotating, the magnets keep passing the coil and the spark plug keep firing based on a specific timing. The ignition system coordinates the timing so that the spark will ignite the air-fuel mixture in the combustion chamber just as it reaches maximum compression in each engine cycle- thus, maximizing the engine’s power. When you start your lawn mower or small engine, you turn the flywheel and its magnets pass the coil (or armature). Push Button starting or Pull Cords (depending on your engine type).Whether you start the engine with a pull rope or the turn of a key on an electric start motor, you're relying on the ignition system to produce a spark inside the combustion chamber. Shipping to: United States, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech Republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, Sweden, Korea, South, Indonesia, Taiwan, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Israel, New Zealand, Philippines, Singapore, Switzerland, Norway, Saudi Arabia, United Arab Emirates, Qatar, Kuwait, Bahrain, Croatia, Republic of, Malaysia, Aruba, Belize, Dominica, Grenada, Saint Kitts-Nevis, Turks and Caicos Islands, Bangladesh, Brunei Darussalam, Bolivia, Egypt, French Guiana, Guernsey, Gibraltar, Guadeloupe, Iceland, Jersey, Jordan, Cambodia, Liechtenstein, Luxembourg, Monaco, Macau, Martinique, Nicaragua, Pakistan, Paraguay, Bahamas, China, Uruguay, Russian Federation, Canada, Sri Lanka, South Africa, Antigua and Barbuda, Saint Lucia, Barbados, Bermuda, Cayman Islands, Maldives, Oman, Reunion, Montserrat, Chile, Colombia, Costa Rica, Dominican Republic, Panama, Trinidad and Tobago, Guatemala, El Salvador, Honduras, Jamaica, UkraineĮxcludes: US Protectorates, APO/FPO, Afghanistan, Kazakhstan, Mongolia, Nepal, Tajikistan, Azerbaijan Republic, Georgia, Turkmenistan, Armenia, Uzbekistan, Bhutan, India, Kyrgyzstan, Vietnam, Laos, Micronesia, Fiji, Papua New Guinea, Solomon Islands, Marshall Islands, Nauru, Wallis and Futuna, Western Samoa, Tonga, Tuvalu, Vanuatu, Kiribati, New Caledonia, Palau, American Samoa, Niue, French Polynesia, Cook Islands, Guam, Greenland, Mexico, Saint Pierre and Miquelon, Ghana, Djibouti, Cape Verde Islands, Mali, Botswana, Sierra Leone, Madagascar, Saint Helena, Seychelles, Gambia, Liberia, Rwanda, Libya, Cameroon, Central African Republic, Gabon Republic, Lesotho, Mayotte, Nigeria, Zimbabwe, Mauritius, Guinea, Côte d'Ivoire (Ivory Coast), Chad, Kenya, Guinea-Bissau, Eritrea, Senegal, Togo, Morocco, Burundi, Equatorial Guinea, Mauritania, Congo, Democratic Republic of the, Congo, Republic of the, Western Sahara, Malawi, Comoros, Angola, Algeria, Benin, Tunisia, Uganda, Zambia, Somalia, Swaziland, Ethiopia, Mozambique, Niger, Tanzania, Namibia, Burkina Faso, Turkey, Yemen, Iraq, Lebanon, Puerto Rico, Saint Vincent and the Grenadines, Netherlands Antilles, Anguilla, British Virgin Islands, Haiti, Virgin Islands (U.S.The ignition system is the starting system for your small engine.