Builder, a 14.7 to 1 air to fuel is the ideal mixture, too rich or too lean are both harder to fire. A choke is used to get fuel into a cold engine with no fuel in the cylinders, kinda priming the pump so to speak. The poor fuel distribution of the log-style intake of the straight six means all cylinders do not get the same mixture, therefore a carb problem will not necessarily affect all cylinders equally. They can be also a source of vacuum leaks when warped which would affect only certain cylinders. Brian
