Thanks for the hot starting suggestions. I'll try that starting trick next
time.
We were able to start instantly when an crew member momentarily lifted the
slide of one of the
carbs. Unfortunately, we had to remove all 4 pins holding the hood/bonnet in
place to do so.
Under these circumstances,it fired right up(once we learned the trick), but
obviously this is far
from ideal. Clearly this points to rich mixture.
I need to study up on SU carbs. I found that starting from dead cold was
always a cinch. However
starting became difficult even after a minimal warm up such as first thing in
the morning,
driving from the pits to (an uncongested) pre-grid. The carbs under these
circumstances remain
at air temperature but still starting had become difficult without the lifting
slide trick.
So the starting difficulty did not seem to be a function of the temperature of
the carb body.
After a race, the carb bodies were very hot, approx too hot to touch which I
suppose puts them
around 60 degrees C. I can image that might disturb the mixture ratio.
I don't understand how the mixture can become relatively richer when the engine
has been run.
Perhaps the hot plugs are less able to fire the rich mixture than cold plugs. I
imagine plug
ceramic cores have low thermal mass and will get hot instantly. The appearance
of the plugs was
fine at all times by the way.
I seem to remember some comments a few months ago about a "must have" book on
SU carbs, can
anyone refresh my recollection? any wisdom about what variables affect these
things would be
nice.
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