EMPI 0.55 Idle Jet for 40/44 HPMX, 40/44/48 IDF, DCNF, & PMO Carburetors

This EMPI .55 idle jet, part 43-5546-0, is a Weber 74405-series jet that controls the idle and off-idle fuel mixture in 40 and 44 HPMX, 40, 44, and 48 IDF, DCNF, and PMO carburetors. A .55 sits mid-range in EMPI's .40 to .70 lineup for these carbs, and it comes installed in EMPI's dual-carb 44 HPMX and in most of PMO's 40mm and 46mm carb sets.

Count throats before you order. A two-barrel IDF or HPMX has two idle jets, so a dual-carb VW needs four, and a flat-six PMO setup needs six. On the HPMX, each idle jet sits in an idle jet holder with an idle jet O-ring (43-6417-0). EMPI's HPMX parts list gives the stock holder no separate part number, so if a holder is damaged or hard to reach, JayCee's brass IDF holder (JC-4313-0) takes a 5/32 inch Allen wrench.

Technical Details

• Manufacturer: EMPI
• Manufacturer part number: 43-5546-0
• Size: 0.55
• Weber series: 74405
• Carburetors: 40/44 HPMX, 40/44/48 IDF, DCNF, PMO
• Sold as: each

Fitment & Compatibility

Fits EMPI 40 and 44 HPMX, Weber 40, 44, and 48 IDF, and Weber DCNF carbs. PMO carburetors for the air-cooled 911 use IDF jets and take it too. The Weber 48 IDA and EMPI EPC 48/51 need a different idle jet.

Installation & Tuning Notes

Keep the jets matched within each carb. On an engine that is otherwise in tune, misfiring under 2,500 rpm means go larger, and bogging at low rpm means go smaller.

Common Questions

Is this one jet or a set of four?
One jet. Order one per throat.

My HPMX keeps clogging idle jets. Is there a fix?
EMPI's 44-1130 Idle Jet Vent Tube Kit adds extended vent tubes to older HPMX and IDF carbs, one kit per carb.