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Product details
EMPI 43-5546-0 is the .55 idle jet in EMPI's Weber 74405-series range, used in EMPI 40 and 44 HPMX, Weber 40, 44, and 48 IDF, and Weber DCNF carburetors to meter fuel from idle to about 2,500 rpm. Its part number sits out of sequence with its neighbors in EMPI's chart. The .52 is 43-5514-0 and the .57 is 43-5515-0, so check numbers carefully when reordering from an old invoice. EMPI's dual-carb 44 HPMX (47-1012-0) leaves the factory with 55 idle jets.
Each HPMX barrel has its own idle jet, main jet, air correction jet, and emulsion tube, and EMPI notes that the HPMX keeps the idle and main circuits separate. The two idle jets in a carb should match. Common companions are the idle jet O-ring (43-6417-0), the .52 and .57 sizes for small steps, and the .60 (43-5516-0) for a richer idle.
Technical Details
- Manufacturer: EMPI
- Manufacturer part number: 43-5546-0
- Calibration: .55
- Pattern: Weber 74405 series
- Used per HPMX carb: 2
- Sold as: each
Fitment & Compatibility
Fits EMPI 40 and 44 HPMX, Weber 40, 44, and 48 IDF, and Weber DCNF carburetors on single or dual carb setups. Weber 48 IDA and EPC 48/51 carbs take EMPI's 43-5536 series, and Weber DCOE carbs take their own F8 or F9 idle jets.
Installation & Tuning Notes
Before changing jets, check for vacuum leaks, set the valves and timing, fit fresh plugs, and sync the carbs. EMPI notes that dirty or plugged idle and main jets are the first place to look when a cylinder is not firing properly.
Common Questions
Does this fit a single 44 HPMX?
Yes. EMPI ships the single-carb version with 60 idle jets, so a .55 there is a leaner choice.
How many do I need for dual carbs?
Four, two per carburetor.
