Flying Horse 2-Stroke/4-Stroke Motorized Bicycle Handle Bar Mounted Digital Engine Tachometer &ndash; Gas Bike RPM Tachometer The Digital Tachometer is perfect for any gas powered motorized bicycle engine, as well as most any gas powered engine Reads both your RPM's (up to 99,999 RPM) and total hours of operation (up to 9999.9 hours). There's also a programmable maintenance interval setting to assure you know where your motor stands Installation is simple: just wrap the first wire around your spark plug chord, then ground the other to your frame or the motor, mount to your handlebars and you're ready to ride Up to 35,000 hours of life (about 2-3 years) off of a quartz battery Works great on both 2-stroke and 4-stroke engines