EMPI 1.75 Air Correction Jet for 40/44 HPMX, 40/44/48 IDF, EPC 48/51, 48 IDA, & DCOE Carburetors

This is EMPI's 1.75 air correction jet, part 43-5416-0, which controls high-rpm mixture in the main circuit of 40/44 HPMX, 40/44/48 IDF, EPC 48/51, 48 IDA, and DCOE carburetors. Common HPMX tuning charts list a 1.75 for a single 40 HPMX on a 1500cc to 1600cc engine and for a single 44 HPMX on 1500cc to 1835cc engines, which makes it a frequent change on single-carburetor street engines. EMPI ships its HPMX carburetors with 1.60 air correctors, so a 1.75 is three steps leaner. Its effect shows mostly from about 3,500 rpm up.

EMPI sells the jets individually, so a single two-barrel HPMX takes two. If a 1.75 is still a little lean at the top, step down to the 1.70. If it runs fat, step up to the 1.80.

Technical Details

• Manufacturer: EMPI
• Manufacturer part number: 43-5416-0
• Type: main-circuit air correction jet (77401-type)
• Size: 1.75
• UPC: 707924223712
• Sold as: each

Fitment & Compatibility

EMPI lists this jet for the 40 and 44 HPMX, the 40, 44, and 48 IDF, the EPC 48 and EPC 51, the 48 IDA, and the DCOE. A progressive EPC 32/36, an EPC 34, or a DGV needs EMPI's other air jet series, and EMPI D carburetors use their own 44-10xx jets.

Installation & Tuning Notes

Before changing jets, check for vacuum leaks, set the valves and timing, fit fresh plugs, and synchronize the carburetors. Then test at steady rpm and change one size at a time.

Common Questions

Which air jet should a single 44 HPMX on a 1641 run?
Common charts list a 1.75 for a single 44 on a 1600cc to 1835cc engine. Treat it as a starting point and confirm with plug readings.

Does a bigger air jet richen the engine?
No. A larger air corrector leans the top end.