I have 100 hours on my engine and EMS. At about 50 hours, I occasionally would have a jumping RPM reading - always jumping to the high side. I was using the output from my Dual Lightspeed boxes and read that the voltage was sometimes too low for the EMS. I switched to a tack drive unit yet the problem still occasionally occurs. There is no particular observable pattern nor occurrence that starts its impression of a Mexican Jumping Bean. So that is two strikes against the EMS for me and leads me to believe that the problem lies with the EMS. Comments please.