Tachometer Tests
NOTE:
DO NOT
reverse polarity when installing tachometer. Damage to diode and transistor may result.
Contact a calibrated, reliable tach-dwell meter to vehicle ignition system. Run engine at varying RPM. If comparision between tach-dwell meter and vehicle tachometer readings do not fall in the standard range of permissible variation, replace vehicle tachometer. For allowable variation see TACHOMETER ALLOWABLE VARIATION .
TACHOMETER ALLOWABLE VARIATION
| Engine RPM | Tachometer RPM Range |
|---|---|
| 1000 | 900-1100 |
| 3000 | 2850-3150 |
| 5000 | 4750-5250 |
| 6000 | 5700-6300 |