Longacre AccuTech Tach Installation and Operation - Manual

Memory Tach
For standard and electronic ignition systems, 12 volt,
negative ground, 4, 6, or 8 cylinder, 4 cycle. NOT for
magneto or Accel BEI or Laser ignition systems.
White wire -
Power for gauge back lites
Connect to ignition switch
so they shut off
with motor.
Red wire -
Power to run tach.
Commonly connected to
ignition switch so tach
shuts off with motor.
Green wire -
Signal wire.
Connect to ignition system.
• Electronic ignition box - connect
to “Tach” terminal on the box
• Other electronic and point sys-
tems connect to Negative (-) side
of coil (NOT big coil wire!).
MSD™ ignition? - see warning
below
Black wire -
Ground. Connect to engine
or frame. Very important.
Many tach problems trace
back to an improper ground
connection.
Misc. Notes:
• Be sure all electrical connection are tight. Clean the surface for
ground connection. Use insulated connectors or soldered.
• Mount tach where it will not receive excess vibration or heat.
• If wires go thru the firewall use a grommet to prevent chafing
and shorts. Keep wires away from exhause heat.
• Tach is water resistant but NOT waterproof. If you wash the car
out cover the tach to keep it dry
.
To Operate Tach
Push “Reset” before going out the first time:
(Black button) This erases the previous memory.
After a run push “Recall” to see highest RPM:
(RED button) The ignition switch must be ON to
recall. However you can shut off the ignition, turn it
back on, and still retain the reading. Push “Reset”
before going back out.
MSD ™ Warning
DO NOT connect tach to an MSD™
coil. Unrepairable damage may occur
and will void Warranty.
Connect to “Tach” terminal on box.
NEVER NEVER
connect any wires from the tach to any
spark plug wire or coil secondary wire!
The tach may be damaged beyond repair
and Warranty will be voided.
Change to 4 or 6 cyl use:
This is done from the front unlike
other tachs. Turn on ignition to
power tach. Press and HOLD
BOTH Reset & Recall buttons.
Pointer will jump to 10,000 RPM,
then drop to 0 (continue to hold
both for 10 seconds). Pointer will
go up to 8000 RPM, indicating 8
cyl. (you can now release both
buttons). Push Recall to change.
6000 = 6 cyl., 4000 = 4 cyl. When
you get the setting you want push
Reset to save setting. Tach will
return to normal function.
7/07
Longacre Racing Products
Monroe, Wa. 360 453 2030
(back of tach)