MIXTURE SCREW for carburetor with M5 thread
$ 7
Part number: ST1669
Made in: EU
MIXTURE SCREW for carburetor with M5 thread
Replacement mixture screw for carburetor idle and low-speed circuit adjustment. This screw meters the mixture at closed throttle and during the progression phase, depending on the carburetor design. Correct screw profile and seating are important for stable idle adjustment, clean throttle pickup, and consistent transient response.
M5 threaded carburetor mixture screw The ST1669 screw is intended for carburetors using the matching M5 threaded interface. It can be used when the original mixture screw is damaged, missing, or has a worn adjustment tip, but the carburetor family and screw geometry must match. The pointed end interfaces with the calibrated mixture passage; damage, incorrect length, or an incompatible seat can prevent accurate adjustment and may contribute to unstable idle or hesitation during initial throttle opening.
This replacement part is suitable for carburetor service and restoration work where the original component is worn, damaged, or missing.
Reference/MPN: ST1669.
Technical role: M5-threaded carburetor mixture screw for adjusting the idle and low-speed mixture circuit.
Service relevance: Replaces a damaged, missing, or worn mixture screw to support stable idle adjustment and clean initial throttle response.
What Is Included
- 1 carburetor mixture screw, MPN ST1669, with M5 thread
- Made in EU.
Important Fitment Note
Verify the carburetor family, manufacturer code, and the original screw marking before ordering. Check the M5 thread, overall geometry, pointed tip profile, seating arrangement, and adjustment-head interface. The image includes a 9 mm marking; compare this measurement and its reference point with the removed screw rather than assuming it represents the complete screw length.
Compare the replacement directly with the removed mixture screw before installation. Confirm that the threaded section engages correctly and that the tip reaches the carburetor’s mixture seat without bottoming prematurely. Use the carburetor’s established adjustment procedure after installation, since mixture-screw position and adjustment direction vary between fuel-screw and air-screw designs.Show all parts
