123ignition 123-TUNE-4-R-V User Manual page 6

parts, using tie-wraps or other suitable means.
GB
Connect the vacuum-tube ( if there is one ) from the carburetter to the nipple on the '123'. Older
engines may have a screw-connection for the vacuum-advance diaphragm. In this case you can use a short
length of rubber hose to connect to the 123, or remove the hard line to the carburetter and replace it
completely with thick-walled rubber vacuum-hose.
If you loaded the proper advance-curve before , you can now start your engine !
LOADING CURVES INTO THE 123\TUNE
Connect the 123\TUNE to your computer, and start the 123\TUNE-software.
Example 1
Go to : 'File' ➔ 'Import from file' ➔ select "example1.xml" and "Import"
This example demonstrates the (quite unpractical) use of maximum 10 points for each curve. The rev.
limiter for this curve is set to 6000 rpm. The MAP-start ( the speed above which the vacuum-curve will
be active ) is set to 1500 rpm.
The vertical grey line in the manifold advance curve, indicates atmosferic pressure. ( 1 bar equals 100
kPascal ) The more you go to the left, the lower the abs. pressure gets, or the higher the vacuum, hence
the vacuum-advance sits in the left, upper part of this curve.
Boost-retard is a term, that stems from supercharged / boosted engines. When the pressure in the
manifold becomes greater then atmospheric, you will have to retard the spark. For this reason, the boost
retard sits in the right, lower part of the curve.