Curious -- who has the highest mileage Z125 on here?
Yes, that's an important clarification. The sensor may be on the same shaft as the front sprocket, but it's actual sensing device is INside the case to read the shaft rpm, and NOT in any way dependant upon the number of teeth on the sprocket. Which leads to an interesting set of circumstances:To say that the pickup or sensor is on the front sprocket would not be accurate. The sensor as was said reads the output or what can be known as counter shaft. it is on the back of the case