Holley Carb

To conclude this series, we’ll remove the bowls and metering blocks from these carbs and look inside.

This time, we’ll examine throttle shafts, baseplates and a not-so-little thing called a “by-pass valve” found on the XP series carbs.

This time around, we’ll dig into the float bowls, accelerator pumps and more.

What we’ll look at here are the differences in the big Holley 4150 carburetors – all with 1.750-inch diameter throttle bores.