Koso DL-03A Air/Fuel ratio meter & RPM data logger with BOSCH® LSU 4.9 sensor

Koso DL-03A Air-Fuel Ratio Gauge with BOSCH® LSU 4.9 Sensor | Tachometer | Digital Voltmeter

The Koso DL-03A is a high-precision air-fuel ratio gauge featuring a BOSCH® LSU 4.9 sensor. It combines a tachometer, digital voltmeter, and five LED indicator lights in one device. The heated display ensures optimal readability even in low temperatures.

Note: Without ABE – not approved for road use.

Main Features & Functions

• Tachometer: 0 ~ 14,000 RPM, 100 RPM per segment, 14 segments

• Air-Fuel Ratio (AFR): 9.0 ~ 24.0 AFR, adjustable in 0.1 AFR steps, 14 segments

• Warning functions:

  • Rich AFR: 9.0 ~ 14.7 AFR (Default: 14.4 AFR)

  • Lean AFR: 14.7 ~ 24.0 AFR (Default: 15.0 AFR)

  • RPM warning: 1,000 ~ 14,000 RPM (Default: 8,000 RPM)

  • Low voltage warning: 8.0 ~ 13.0 V (Default: 11.5 V)

• Recording: Stores up to 50 runs, max. 99 min 59 sec per run, total capacity approx. 3.15 hours

• Records maximum RPM and AFR values for each run

• Backlight: 5 brightness levels (Default: 5)

• Suitable for 2-stroke and 4-stroke engines (requires “2-Stroke Adaptor” BG001855 for 2-stroke engines)

Technical Data

• Operating voltage: DC 12V

• Digital voltmeter: 8.0 ~ 13.0 V

• Operating temperature: -10 ~ +60°C

• Standard: JIS D 0203 (S2)

• Size: 72 × 32.3 mm

• Weight: approx. 100 g

The Koso DL-03A is a compact and versatile instrument, ideal for tuning, racing, and demanding conditions, providing precise AFR and RPM monitoring.