Hi John,
I must have missed the Kitfox recommendation. As far as checking the accuracy of my tach, yes and no. I have both the Grand Rapids EIS2000 which gives the RPM in digital format as well as the analog AviaSport Rotax 912 tach and they both agree. Because they both trigger off the same signal provided by the engine, its not a true validation like as would be provided by a handheld laser RPM meter.