Fitment questions?
Call (855) 786-7101 or text (801) 304-3141.
Real people. Real answers.
Product details
EMPI's 1.40 main jet, part 43-5307-0, sets main-circuit fuel flow in the EMPI 40/44 HPMX, Weber 40/44/48 IDF, EMPI EPC 48/51, Weber 48 IDA, and Weber DCO/DCOE carburetors. It is the main jet EMPI installs in its 44mm HPMX for single-carb setups (47-1012-2), which ships with 140 mains, 160 air correctors, F11 emulsion tubes, 30mm venturis, and 60 idle jets.
The HPMX, IDF, and IDA are downdrafts and the DCO/DCOE is a sidedraft, but EMPI uses this one jet for all of them. Each barrel has its own main jet, so a single two-barrel carb takes two. When the venturi changes, the jetting usually follows. EMPI makes a 34mm venturi (43-5610-0) for the 40/44 HPMX and 44 IDF, and air correction jets from 1.00 to 2.20.
Technical Details
- Manufacturer: EMPI
- Manufacturer part number: 43-5307-0
- Jet type: main jet
- Size: 1.40 mm
- Carburetors: 40/44 HPMX, 40/44/48 IDF, EPC 48/51, 48 IDA, and DCO/DCOE
- Sold as: each
Fitment & Compatibility
Confirm your carburetor model first. Weber DGV, DFV, and ICT carbs and EMPI EPC 32/36, 34, and 38 models use a separate jet series, and Kadron-style 40K carbs use Solex-pattern jets.
Installation & Tuning Notes
A larger main adds fuel across the main circuit, while the air corrector mainly trims the top end. Change one at a time so you know which part made the difference.
Common Questions
Is 1.40 the stock main jet in an EMPI 44 HPMX?
In the single-carb version, yes. The dual-carb 44 HPMX ships with 135 mains.
Does this fit a DCOE sidedraft as well as an IDF?
Yes. EMPI lists the same 1.40 for DCO/DCOE sidedrafts and for IDF, IDA, HPMX, and EPC 48/51 downdrafts.
PMB Performance has been tuning air-cooled VW and Porsche carburetors for over 20 years.
