KUS Universal 85mm Tachometer with Hourmeter and 4-LED Alarm Instruction Manual

1. Product Overview

The KUS Universal 85mm Tachometer is designed to accurately display the engine's rotation speed (RPM) and includes an integrated hourmeter. It features a 4-LED alarm system for critical engine parameters and a red backlight for clear visibility. This robust gauge is suitable for a wide range of applications including cars, motorcycles, trucks, boats, and yachts.

Key Features:

• Suitable for various tacho sensors.
• Moving-magnet principle for good endurance and anti-vibration.
• IP67 protection rank, completely waterproof.
• 316 Stainless steel bezel with curved glass.
• Convenient multi-plug socket connection.
• LCD display and stepper motor operation.
• Excellent anti-fogging function.

2. Specifications

Compatible Tacho Sensors:

• M16*1.5 (2-wires): Operating temperature: -40 ~85℃, Output signal: sine wave, Signal duty factor: 47±5%, Inductance distance: less than 1mm, Tooth module: 2~6, Connecting way: two wires, Protection rank: IP65.
• M16*1.5/M18*1.5 Holzer Tacho (3-wires): Operating temperature: -40 ~85℃, Output signal: square wave, Inductance distance: less than 2mm, Operating voltage: 8~32V with polarity protection, Connecting way: three wires, Protection rank: IP65.
• M18*1.5 M16*1.5 (2-terminals): Operating Temperature: -40 to 85℃, Output Signal: Sine Wave, Signal Duty Factor: 47±5%, Inductance Distance: Less than 1mm, Tooth Module: 2~6, Connecting Way: Two Terminals connection.

Image: Example of an M16x1.5 Tacho Sensor.

3. Installation

Panel Mounting:

1. Cut an 85mm (3-3/8") diameter hole in your panel. Ensure a minimum clearance of 55mm (2-3/16") behind the panel for the gauge.
2. Remove the fastening ring from the gauge.
3. Insert the gauge into the panel hole.
4. Adjust the gauge's position as desired, then secure it by tightening the fastening ring from the rear.

Wiring Connection:

Connect the wiring harness to the gauge according to the diagram below. The gauge requires a 12VDC power supply.

Image: Detailed installation steps and wiring diagram for the tachometer.

Wiring Color Code:

• Red: +12V (Positive Power)
• Blue: Ground (-)
• Black: To RPM signal input
• Orange: Temperature alarm signal input
• Yellow: Low oil alarm signal input
• Brown: Red Backlight (+)
• Blue: Pressure alarm signal input
• Green: CHK ENG alarm signal input

Tacho Sensor Installation:

The sensor is typically mounted on the flywheel casing of the engine. For optimal performance, ensure the sensor is positioned vertically to the top surface of the engine's flywheel. The inductance distance should be less than 1mm for 2-wire systems and less than 2mm for 3-wire systems.

Image: Tacho sensor installation details and main technical parameters for different sensor types.

4. Operation

Speed Ratio Adjustment:

The speed ratio needs to be adjusted to match your engine's signal output. The adjustable range is 1.0-10.0.

1. Ensure the gauge is powered on.
2. Long press the black button on the back of the gauge for 3 seconds to enter the setting mode. The display will show the current speed ratio.
3. While in setting mode, a short press of the black button will increase the speed ratio.
4. To decrease the speed ratio, release the button and then long press it again.
5. Once the desired speed ratio is set, release the button and wait for 3 seconds (or long press again for 3 seconds) to exit the setup mode. The gauge will automatically save the setting.

Note: The gauge should be powered before setting the speed ratio. If the tachometer does not respond correctly after setting, consider adding a 230 Ohm (1/4W-1W) resistor in series with the signal wire to strengthen the signal. A 20K potentiometer can be used for testing.

Alarm Functions:

The tachometer features 4 LED alarm indicators for critical engine conditions. These alarms are triggered by low-level voltage signals from their respective sensors.

• Low Pressure Alarm: Indicates low oil pressure.
• High Water Temp Alarm: Indicates high engine water temperature.
• CHK ENG (Check Engine) Alarm: Indicates a general engine fault.
• Low Fuel Alarm: Indicates low fuel level.

The specific alarm thresholds for oil pressure, water temperature, and oil level depend on the sensors connected to the system.

5. Maintenance

To ensure the longevity and accurate operation of your KUS Tachometer, follow these maintenance guidelines:

• Cleaning: Use a soft, damp cloth to clean the gauge face and bezel. Avoid abrasive cleaners, solvents, or harsh chemicals that could damage the finish or the curved glass.
• Inspection: Periodically check all wiring connections to ensure they are secure and free from corrosion.
• Environmental Protection: Although the gauge has an IP67 waterproof rating, prolonged exposure to extreme conditions or direct high-pressure water jets should be avoided.
• Sensor Care: Ensure the tacho sensor is clean and free from debris that could interfere with its operation.

6. Troubleshooting

If you encounter issues with your tachometer, refer to the following common problems and solutions:

• Tachometer not displaying RPM or displaying incorrect RPM:
  • Verify that the speed ratio is correctly set according to your engine's specifications (refer to Section 4).
  • Check all wiring connections for looseness, corrosion, or incorrect polarity.
  • Ensure the tacho sensor is properly installed and functioning.
  • If the signal is weak, consider adding a 230 Ohm resistor (1/4W-1W) in series with the signal wire to boost the signal. A 20K potentiometer can be used for testing signal strength.
• Alarm LEDs not functioning or false alarms:
  • Check the wiring to the respective alarm sensors.
  • Verify the alarm thresholds of your sensors are appropriate for your engine's operating conditions.
  • Ensure the sensors themselves are functioning correctly.
• No backlight:
  • Check the brown wire connection for the backlight to ensure it has a positive 12VDC supply.
  • Inspect the wiring for any breaks or shorts.

7. User Tips

Based on common user experiences, here are some tips for optimal use:

• Pre-installation Check: Before final installation, temporarily connect the gauge and power it up to verify basic functionality and to set the speed ratio. This saves time and effort.
• Sensor Compatibility: Always ensure your chosen tacho sensor (2-wire or 3-wire Holzer) is compatible with your engine type and the gauge's input requirements.
• Signal Integrity: For engines with potentially noisy RPM signals, the suggested resistor/potentiometer addition can significantly improve reading stability.
• Panel Hole Precision: A precise 85mm (3-3/8") panel hole is crucial for a snug and waterproof fit. Use appropriate tools for cutting.

8. Warranty & Support

For warranty information and technical support, please refer to the seller's policies or contact the manufacturer directly. Keep your purchase receipt as proof of purchase.