ou’ll never be able to accurately and effectively tune a motorcycle without first knowing its air/fuel ratio (AFR). Lacking that basic bit of information you’re just shooting in the dark making your adjustments, and it makes no difference if that bike is carbureted or fuel-injected. If you don’t have access to a dyno with an exhaust sniffer, or you need to do on-track/on-road testing, the low-cost WEGO III is the answer. The WEGO III is the third generation of Daytona Sensors reliable, race proven WEGO (Wide-band Exhaust Gas Oxygen) technology and it offers complete AFR metering with built-in data logging. This versatile tuning aid and diagnostic tool is easy to install, easy to use, it’s reasonably priced and it works for all fuel injected and carbureted four-stroke gasoline engines.
     Installation is easy. The WEGO III requires power and ground connections, that’s it. It comes with a 42-inch harness for motorcycle applications, there’s a Bosch LSU4.2 5-wire sensor, an 18 x 1.5 mm weld nut (should it be needed) to install that sensor and date logging software on CD ROM. To log RPM you must also connect a tach signal, and some Japanese bikes with CD type ignition will require an optional tach adapter. Daytona Sensors has a special tech note for Hayabusa applications on their website at www.daytona-sensors.com. If you’re tuning a bike with an exhaust system lacking an oxygen sensor fitting you can easily fabricate an exhaust sniffer for temporary mounting, too, and Daytona Sensors has a tech note on that. It also describes a new tube sniffer design that solves dyno tuning problems caused by reversion effects on open exhausts.
     Once hooked up the WEGO III will display the AFR and can log over two hours of data including AFR, engine RPM and there’s a spare 0-5 volt analog input for sensing functions such as throttle position or manifold pressure. An ultra-bright and daylight readable blue LED displays all the information needed to make knowledgeable tuning adjustments. This unit is highly accurate, too; there’s less than ±0.10 AFR error over the 10.3 to 19.5 AFR range. The WEGO III is fully encapsulated and it’s waterproof. It’s tough.
     dSo, don’t have a dyno or an exhaust-gas sniffer? You do now with the WEGO III. It’s available at Parts Unlimited, Part #1022-0054.