Calibration Test
Connect a calibrated, reliable tach-dwell meter to vehicle ignition system. Operate engine at various speeds (RPM). See TACHOMETER ALLOWABLE VARIATION . If comparison between tach-dwell meter and vehicle tachometer readings are not within permissible variation, replace vehicle tachometer.
TACHOMETER ALLOWABLE VARIATION
| Engine Speed (RPM) | Allowable Variation (RPM) | |
|---|---|---|
| 8000-RPM Tachometer | ||
| 700 | 600-800 | |
| 3000 | 2850-3150 | |
| 5000 | 4750-5250 | |
| 9000-RPM Tachometer | ||
| 700 | 600-800 | |
| 3000 | 2900-3225 | |
| 5000 | 4900-5325 | |