I've tried this once on my '73 TR6 and I thought it was useless. The way
it works is this: They provide you with a dummy spark plug device with a
sort-of "looking glass" built in. You install this in place of one spark
plug and then run the engine. You look through the looking glass and check
the color of the flash/flame inside the combustion chamber. One color is
rich, one color is lean, and one color is just right. The trouble I had
was that I could not perceive any difference in the color of the flame when
I adjusted the mixture. I went all the way out to "full-rich" and all the
way in to "full-lean" on the needle adjustment and could not tell any
difference at all. It was very disappointing. Luckily, I was just
borrowing the kit so I wasn't out any $dough$.
To be fair, I've spoken to some folks who've said that the newer
emissions-equipped carburettors like the Zenith-Strombergs will frustrate
anyone with a Colortune kit. The explanation went something like this: ZS
carbs have a very small swing between full-rich and full-lean, and this is
why I didn't see any different colors in there. On the other hand, an
older SU for example, apparently has a much larger swing between rich and
lean. The guy I borrowed the kit from had an Austin Healey 100/6 and he
swore by that Colortune kit... said it worked GREAT!
You all can expand on this, or correct me if I'm wrong or misunderstanding
something.
Pete Chadwell
1973 TR6
|