|Window into the ( car's ) soul
Question : MY friends tell me that a spark plug replacement device can
be used to tune the air-fuel mixture on my carbureted 1980 Mercedes Benz 190E.
I have never heard of a
device and I am unable to find
any literature on it.
Does such a device exist
and, if so, is it a useful addition to the DIY toolbox?
SUCH a device certainly does
exist and is manufactured by a
company named Gunsons in the
The device is known as Colortune and is a spark plug
with a quartz window.
The Colortune device is fitted
in place of one of your engine's
spark plugs and the colour of
the combustion flame is
observed through the quartz
The mixture is adjusted until
the flame turns blue, indicating
that the mixture is at an optimum.
A word of warning though --
the degree of accuracy achieved
by this method of tuning is
unlikely to be highly precise
although, in most cases, it
should suffice for older vehicles.
It is, however, a useful and
relatively inexpensive addition
to the home mechanic's toolbox.