Document # 31-0008
LM2_Manual_1.4.doc
32
5. You will not have the option to select the ‘Polarity.’ Rising Edge is the most
common way to measure a tach signal. If you find that your readings are very
erratic you should change this setting to Falling Edge. Press
Enter
.
6. Select the RPM range. Options are 10230 RPM or 20460 RPM. Press
Enter
..
7. Select Pulses per Rotation. Below are two tables to aid in your selection:
Cylinder number and RPM calibrate number 4 Cyl engine
Number
of
Cylinders
4-Stroke
pulses/Crank-
Rotation
Calibrate
Number
Comment
1
1/2
1
Use also when using inductive
clamp on spark wire or power
wire of COP system of 1 cylinder
only for all cylinder numbers
2
1
2
Use also when using inductive
clamp on spark wire or power
wire of Waste spark coil of 1
cylinder only.
Waste spark system:
1 coil for every 2 cylinders.
3 1-1/2
3
4 2
4
5 2-1/2
5
6 3
6
8 4
7
10 10
8
12 12
9
Cylinder number and RPM calibrate number 2 Cycle and Rotary Engine
Number
of
Cylinders
2-Stroke
pulses/Crank-
Rotation
Calibrate
Number
Comment
1
1
2
Use also when using inductive
clamp on spark wire or power
wire of COP system of 1 cylinder
only for all cylinder numbers
Also use for rotary engine.
2
2
4
Use also when using inductive
clamp on spark wire or power
wire of Waste spark coil of 1
cylinder only.
Waste spark system:
1 coil for every 2 cylinders.
3 3
6
4 4
8
5 5
8
