MaxTowDouble Vision 10,000 RPM Tachometer Gauge - for 1-10 Cylinder Gas Powered Engines - Black Gauge Face - Green LED Illuminated Dial - Analog & Digital Readouts - 2-1/16" 52mm

way too small for the application,

After two weeks it quit working properly. While the motor idled the tack read 0 rpm and would jump up to 8000/9000 rpm

Don't waste your money. It jumps all over the place. Only time it reads correctly is at idle. Looks pretty, doesn't work as designed.