 |
|
 |
My Tach Pointer is Erratic/Jumpy?
|
1.) Is your tach pointer jumpy only at idle? This may be due to a 4 cylinder 1 or 2 pulse calibration setting. A little jumpiness at idle is considered normal in this case due to the low frequency signal generated by this ignition signal type at idle. A fluctuation of this type at low engine speeds is a trade off for an extremely quick and smooth reaction at higher engine RPM (where it really counts!) on these types of ignitions.
|
|
|
|
2.) If the tachometer is wildly erratic or jumpy all over the scale, it could be due to in-correct installation or because you are running a Magneto type distributor. If you are running a Magneto, you MUST make sure that you are using suppression core spark plug wires. A classic symptom of using solid core wires with a Magneto is a jumpy, mis-reading, or erratic pointer. This is especially evident when revving the engine or placing it under load. Good quality suppression core plug wires will usually help or solve the problem without a negative effect on ignition system performance.
|
|
|
3.) The issue could be related to a noisy ignition system. Sometimes we have a great deal of luck by putting a 10k ohm, 1/2 watt resistor in line with the signal wire. Check out the video here for more information:
|
|
|
|
|
|