Prüfung und Justage eines Fliehkraftzündverstellers

Contents: An Isetta engine does not drop to idle speed quickly enough when the accelerator is released. Carburetor-related faults are ruled out after numerous tests. It is suspected that the centrifugal ignition advance mechanism is malfunctioning. To investigate this, the centrifugal ignition advance mechanism is tested on a test bench at various engine speeds. It is found that it is setting the ignition timing up to 15 degrees too early in the crankshaft angle. The cause is found to be the wrong, too weak spring on one of the two centrifugal weights. The unsuitable spring is replaced with a standard one, and the centrifugal ignition advance mechanism is readjusted. Final measurements show that its advance curve is once again within the Bosch specification.