what does everyone use for a tach to set there idle for setting the timing. i have a auto digital tach but i can only turn it down to 4 cylinder. i devide that rpm in half but it doesnt sound right. my bike, when cold, idles on the digital tach at 900 rpm, which would be 450 rpm, but when i check my timing it is right on, then when it warms up the tach says 1400 rpm, which would be 700 rpm, the idle then seems just about right or a little fast. at 900 rpm on the digital tach the timing is right on and at 1400 it shows between 35-40 degrees advanced.