Chinese Tacho

[rickster g]

Hey guy`s has anyone found issues with cheap eBay replacement tachs under reading ie; showing 3000-4000rpm at a real rpm of approx 7000rpm its the small round chrome case type with the black, green, yellow/black wires and with red ,black light illumination wires. Do these tachs have to be ratio sensitive.
Would be really grateful for any feedback on electronic tach replacements and how they wire up/connect .

 

[tstidham]

You can find electronic ones that will use a pickup wire that you wrap around one of the spark plug wires or a traditional negative wire of the coil style. Often they have a switch for the number of cylinders, but this would be more geared towards automotive, shared coil engines. With individual coils per cylinder, this wont matter. As for the mechanical style, since our tachs are driven from the camshaft, it likely has a 2:1 ratio since all camshafts spin at 1/2 of crankshaft speed on 4 stroke engines. Your best bet is likely to be from motorcycle specific websites like mikesxs or similar.