In a message dated 9/28/05 1:15:32 PM US Mountain Standard Time, pp2 at 6007.us writes: > ps used HZ readout on DVM to check idle. Figure 40 HZ = 800 Rpm but was > reading 300 hz (6000 rpm) at est 2500 same as archaeic Dwell Tach. Hummm, 800 rpm = 400 rpm at dist. 400 X 6 sparks per = 2400 Hz doesn't it? Regards, Bob Helt