by David Vizard

 (Taken from David Vizard's How to Super Tune and Modify Holley Carburetors)

If it’s the first time starting a newly installed engine either in the vehicle or on the engine dyno, I go in there with it. This allows me to get the enrichment required to start a cold and totally dry engine by operating the throttle to activate the accelerator pump system. At this stage, getting the engine to idle is a bigger priority than getting the choke to function.

If the carb has a mechanical choke, the driver directs its operation on an as-needed basis. This in effect means there is no real setup involved. If we are talking about electric chokes, the situation is a little different.

Most of the electric chokes on Holley-style carbs come with the preset that takes into account the average temperature conditions seen during the year in the United States. You only make adjustments when the weather conditions show that it is required.

For the very cold weather in northern states, it is often necessary to adjust the bi-metal spring housing so the choke stays on longer. In the hotter climes of southern states it can save a little fuel by having the choke come off a little sooner.

If it is necessary, adjustment of the electric choke is simple. To hold the choke on longer, rotate the housing.

Any good parts store sells inexpensive large-dial vacuum gauges, such as this one.