One problem may be the spark plug. Remove the plug to see if itâ€™s fouled by excess oil, dirt or debris. If so, replace it. Spark plugs can be removed and installed using a special spark plug socket with a ratchet. Sometimes the plug may not be fouled, but a small amount of debris may have collected in the spark gap area, interfering with proper ignition. In this case, you may solve the problem by removing the debris and cleaning the spark gap area with carburetor cleaner. In general though, itâ€™s best to just replace the plug if thereâ€™s any question about its reliability.
If the problem is occurring with a new plug that does not appear fouled at all, check to make sure the spark gap is set correctly. Consult your Craftsman small engine service manual to find the correct gap and use a gap tester to check your plug. If the gap is too large, push the hook part of the plug against a hard surface to narrow the gap until it tests to the proper distance.
You can find the model and serial numbers located on the engine cover by the flywheel screen or recoil area.