IH: Carburetor, Intake Manifold & Exhaust Systems - Sub-01B

See also in the Sportsterpedia:

• Bendix basic carb information
• Bendix Carb Functions, Adjustments, Tuning

There were three Bendix carburetors, designated in the parts catalogs, that were installed on Sportsters.

Additionally, 27152-71A (38mm) was reportedly factory installed on a '74 XLH delivered from the dealer in July 1974. ⁶⁾

Both of these carbs are stamped 27152-71.
One has a '36'.
The other has a '38' stamped inside the venture.

27152-71A (13732) - venturi stamped '38' 8) 9)

27152-71 (13479) and an arbitrary 'A' - venturi stamped '36' 10)		27152-71 (13479) and an arbitrary 'E' 36mm, fixed jet 11)

27152-71 (13479) and an arbitrary 'E', 38mm, adjustable jet 12)

The venturi size is cast into the venturi. ¹³⁾
Looking in the carb from the air cleaner end, the numbers are on the venturi at 12:00 o'clock on the radiused entry.
They are small but every bendix should have the number stamped there.

¹⁴⁾

Side by side comparison of 36mm and 38mm Bendix carbs.
Aside from the venturi size, the other main difference that might affect the way it runs is the number of secondary idle discharge ports.
These are the holes that get uncovered by the throttle plate at part throttle settings.
The 38mm has 3 (in addition to the idle adjustment screw hole).
The 36 has 2 (in addition to the idle adjustment screw hole).
The air cleaner screw bosses on the 36mm are smaller.

(Left) 38mm, (Right) 36mm 15)	36mm doesn't have a bowl vent hole here 16)	(L) 38mm has a flat corner, (R) 36mm is round 17)

The 36mm carb has 3 idle passages. ¹⁸⁾
The 38mm carb has 4 idle passages.

One feature of an adjustable main jet, (besides the number), is the holes near the bottom that are drilled at about a 45° angle. ¹⁹⁾
Note that on the adjustable main jet shown below (R), the top of it looks identical to the fixed jet. ²⁰⁾

²¹⁾

Some have converted their fixed main jet setup to an adjustable jet.

On carbs with the welch plugged main, you can easily convert back to a screw in tube by removing the plug and pushing out the pressed in tube. ²²⁾
You'll need to thread the body with a somewhat uncommon 9/32“-32 tap. But there may be no advantage to doing this.

This adjustable main jet has the tube extending beyond the taper. ²³⁾

Bendix C66-184 adjustable main jet 24)