HFWHOK Small Engine Tachometer, Style C, Digital RPM Meter and Hour Gauge up to 18,000 RPM with Backlit Display and Service Timer

HFWHOK Small Engine Tachometer is a compact digital RPM meter and hour gauge that clips to the spark plug wire to display engine speed, run time, and a programmable maintenance reminder.

This handheld/vehicle-mounted tachometer combines RPM measurement, elapsed-hours tracking and a service countdown in one battery-powered instrument. It installs quickly with a sturdy bracket and a spark-plug clip — no wired power hookup needed — and keeps stored data while you change the battery. With a clear backlit display, programmable RPM alarm and support for both contact and short-range wireless sensing, it works across many gasoline engines from lawn mowers to snowmobiles.

How accurate and wide-ranging is the RPM reading?

The HFWHOK tachometer reads engine speed from 0 up to 18,000 RPM with a quoted accuracy around ±10 RPM and a refresh update roughly every 0.5 seconds. It’s suitable for small gasoline engines where quick RPM feedback helps tune performance or protect the engine from overspeeding.

• Measurement range: 0–18,000 RPM
• Typical accuracy: ±10 RPM
• Refresh rate: approximately 0.5 seconds
• Programmable RPM alarm with red backlight warning

How does the hour meter and service timer work?

This unit tracks total operating hours with 0.1-hour resolution and stores timing data even when you replace the battery. The SVC (service) countdown can be set from 0 to 500 hours to remind you when maintenance is due, and you can reset or return the device to factory defaults from the settings menu.

• Timing range: 0–9,999 hours with 0.1-hour accuracy
• SVC default: 50 hours (adjustable 0–500 hours)
• Settings adjusted via M and S buttons; long-press restores factory settings
• Data retention while replacing battery

How easy is installation and sensing on different machines?

Install the tachometer with the included bracket that secures to round tubes or other mounting points; then clamp the sensing clip to the spark plug wire or use short-range wireless sensing within 3–5 cm. No external power wiring is required — the unit runs on an internal battery and includes low-battery detection.

• Mounts to tubular frames with supplied bracket
• Sensing methods: clip-on spark plug wire or wireless induction
• Optimal wireless sensing distance: 3–5 cm
• Included ~2.2 m wire for flexible routing

What display, alarm and convenience features are included?

The screen (40 x 22 mm) uses a green backlight for normal viewing and turns red when RPM exceeds the programmed alarm threshold. The tachometer supports multiple display modes (RPM, MAX RPM, clock, memory functions) plus auto-sleep and reset capabilities to save battery life. Battery-level indicator and memory recall simplify long-term monitoring.

• Screen size: 40 × 22 mm with green default backlight
• Red backlight triggers when RPM alarm is exceeded
• Modes: TOT/JOB/SVC/MAX RPM/RPM/clock/memory
• Auto-sleep, reset function, and battery low alert

Who this is for: If you maintain small gasoline engines — from push mowers, trimmers and go-karts to motorcycles, ATVs, snowmobiles and small boats — and need a compact, battery-powered tachometer with run-time tracking and a settable service reminder, the HFWHOK Small Engine Tachometer is designed for rapid installation, clear RPM feedback and basic maintenance scheduling without complex wiring.