Small Engine RPM Tachometer :The digital tachometer can accurately measure the rotational speed of all strokes (cylinders 1-8),including 2-stroke or 4-stroke gasoline engines,timing range with 1-99999 min , RPM Range of 100-30000 rpm,Accuracy with 1%，which enhance the engines safety and reliability 4 Modes Guide:The tachometer has 4 modes (01, 02, 03, 04). Modes 01, 02, and 03 follow a simple doubling relationship (e.g., 01 = 1×, 02 = 2×, 03 = 4×); Mode 04 is for reset only;Please note: Mode 02 ≠ 2-stroke engines, and Mode 03 ≠ 4-stroke engines;To select the correct mode, you can test all modes while the engine is idling and choose the one whose RPM reading is closest to the actual engine speed Zero & Reset Function: Press "MODE" and "SET" together until the screen fills to clear data. Hold "SET" until the screen shows "04" and stops flashing to reset Energy saving Mode: when the gasoline engine is not working, the tachometer will automatically save energy and power, and automatically turn off the display; when the gasoline engine is working, the tachometer will automatically start the test EASY INSTALLATION: With the inductive function and the copper clips ,you can get the working signal by 2 ways (inductive or signal pickup wire );When using the inductive function,you can mount or hold the tachometer to the place can sensing the vibration ; When using the signal pickup wire ,just clamp the spark plug wire with the clip to receive the signal, safe and reliable WIDELY APPLY AS ENGINE MAINTENANCE TOOL:You can use the small engine tachometer as a maintenance Reminder for Lawn Mower Generator Cropper Motorcycle ATV Outboard Motor Dirt Bike Chainsaw;The Digital Tachometer is widely used to measure all any gasoline engine(cylinders 1-8),inchuding 2 or 4-stroke gasoline engines Digital Tachometer - Chainsaw Tachometer Tach Gauge Digital Display Pulse Speedometer for Chain Saw Cropper Generator Lawn Mower RV ATV Dirt Bike Motocross Boat Tractor