Product Overview
The YOOREAL Digital Maintenance Hours Meter and Tachometer (Model YR-HM027A) is designed to monitor engine operation time and RPM for various small engines, including those found in garden mowers, tractors, generators, outboard motors, snowblowers, and pressure washers. It provides essential data for timely maintenance and optimal engine performance.

Image: The Yooreal Digital Maintenance Hours Meter, showing its compact design and attached wiring.
- Hours Counter: Tracks total and partial engine operating hours, with an initial hours programming feature.
- Maintenance Timer (SVC): Allows setting countdown timers for service intervals, such as oil or air filter changes.
- RPM Gauge: Displays real-time engine RPM and maximum RPM, with an adjustable alert RPM function to prevent overspeeding.
- Easy Installation: Designed for straightforward installation using either adhesive or screws.
- Durability: Features a built-in replaceable CR2032 battery and favorable waterproof resistance (IP67).
Safety Information
This product contains a button cell battery. Button cell batteries can cause severe internal chemical burns if swallowed. Keep new and used batteries away from children. Seek immediate medical attention if a battery is swallowed or inserted into any part of the body.

Image: Multi-language warning label regarding the dangers of button cell batteries if swallowed.
Setup and Installation
Before installation, ensure the product surface and the mounting location are free from moisture or grease.
Battery Activation
The device comes with a pre-installed CR2032 battery. Before first use, remove the insulating sheet from the battery compartment to activate the meter.

Image: Rear view of the meter showing the replaceable CR2032 battery compartment and product dimensions.
Wiring for Signal Pickup
Connect the red wire by wrapping it 5-8 times around the spark plug wire. The black wire is for ground, which helps in achieving a more stable signal. The red wire has a length of 5.74 ft (1.75m) and can be shortened or extended (not exceeding 9.84 ft) as needed.
Mounting Options
The meter can be mounted using either the provided adhesive velcro or screws.

Image: Step-by-step diagrams illustrating both velcro and screw installation methods for the meter.
- Velcro Installation:
- Clean the mounting surface thoroughly.
- Apply the adhesive velcro to the back of the meter.
- Press the meter firmly onto the desired clean, dry surface.
- Screw Installation:
- Use the provided cut-out sticker to mark the drilling locations.
- Drill pilot holes as marked.
- Secure the meter using the provided screws and washers.

Image: A comprehensive list of included product accessories, such as the meter, user manual, velcro, battery, cable ties, screws, and cut-out sticker.
Operating Instructions
Hours Counter (TOT)
The meter tracks the total operating hours of the engine. The timing range is 0 to 99999 hours. For new meter replacements, an initial hours value can be programmed within 1 hour before the engine starts working.
Partial Hours (JOB)
This feature allows tracking of partial operating hours, which can be reset for individual tasks or job durations.
Service Interval Timer (SVC)
Set maintenance timers to remind you when service is due (e.g., oil changes, air filter replacement). The maintenance timers can be set from 5 to 2000 hours, with an 'OFF' selection option.

Image: Display showing Total Hours (TOT), resettable Partial Hours (JOB), and Service Interval Time (SVC) with their respective timing ranges.
RPM Gauge
Monitor the engine's revolutions per minute (RPM) and maximum RPM. The RPM range is 0-25000 RPM. You can set an Alert RPM to prevent engine overspeeding. The meter also features programmable engine firing patterns to adjust idle speed status.

Image: Display showing current RPM, Max RPM, and Alert RPM settings, along with a table of programmable firing patterns.
24-Hour Clock
The device also includes a 24-hour clock display.
Maintenance
The YOOREAL meter is designed for low maintenance. The built-in CR2032 battery is replaceable, ensuring long endurance. The device has a favorable waterproof resistance rating of IP67, protecting it from dust and immersion in water up to 1 meter for 30 minutes.

Image: Illustration of the meter submerged in water, demonstrating its IP67 waterproof rating, along with examples of compatible outdoor power equipment.
For battery replacement, refer to the battery activation section under "Setup and Installation" for instructions on accessing the battery compartment.
Troubleshooting
If you encounter issues with your YOOREAL Digital Maintenance Hours Meter, consider the following common troubleshooting steps:
- No Display/Meter Not Turning On:
- Ensure the insulating sheet has been removed from the CR2032 battery.
- Check if the CR2032 battery is correctly installed and has sufficient charge. Replace if necessary.
- Inaccurate RPM/Hours Reading:
- Verify that the red signal wire is securely wrapped 5-8 times around the spark plug wire.
- Ensure the black ground wire is properly connected for a stable signal.
- Check for any damage to the signal wires.
- Confirm the correct engine firing pattern is selected in the meter settings.
- Buttons Not Responding:
- Ensure the meter is not exposed to extreme temperatures or moisture beyond its IP67 rating.
- Try removing and reinserting the battery to reset the device.
If problems persist after attempting these steps, please contact YOOREAL customer support for further assistance.
Specifications
| Brand | YOOREAL |
| Model Number | YR-HM027A |
| Material | Plastic |
| Dimensions (L x W x H) | 3.15 x 1.56 x 0.79 inches (80 x 39.6 x 20 mm) |
| Item Weight | 3.1 ounces (88 Grams) |
| UPC | 787997589717 |
| Hours Tracking Range (TOT) | 0 to 99999 H |
| Maintenance Timer Range (SVC) | 5 to 2000 H / OFF |
| RPM Range | 0 to 25000 RPM |
| Refresh Rate | 0.5s/1s |
| Resolution | 10 RPM |
| Alert RPM Range | 1000-25000 RPM with OFF selection |
| Battery Type | CR2032 Lithium Metal (included, replaceable) |
| Waterproof Rating | IP67 |
| Clock System | 24-H |
Warranty and Support
YOOREAL provides a 2-year guarantee for this product, backed by excellent after-sales and technical group support. During this period, if there is any quality problem with the product, YOOREAL provides free replacement service.
For any inquiries or assistance, the YOOREAL Care Team is available 7 days a week, 24 hours a day, offering professional customer support and hassle-free replacement/return services.