Cvk Pilot Jet (# 38) for Scooters & Mopeds

Cvk Pilot Jet for Genuine Buddy Scooters and GY6 Engines

The Cvk Pilot Jet (#38) suits Genuine Buddy 125 and 150 scooters, plus 139QMB and GY6 engines that use CVK or PWK carburetors. In the fuel system, this jet controls how fuel is metered, so it has a direct effect on engine performance. It is one of the scooter carburetors & jets you can swap to adjust your scooter's setup. Changing the jetting can make a noticeable difference in acceleration and throttle response.

Build and Fit Details

This jet has a round design and is made to tight tolerances. The M6x0.75 thread keeps it firmly seated, and its 28mm overall length lets it install properly in compatible carburetors. It works with several engine codes, so it can be used across a range of scooter models.

Signs It Needs Replacing

Sluggish acceleration or rough, uneven idling can indicate that the pilot jet needs attention. Routine upkeep and occasional jetting checks help keep the engine running well. This part matters most when you are tuning a scooter for stronger power delivery.

Specifications

• Type: Keihin round-style main jet
• Thread Size: M6x0.75
• Overall Length: 28mm
• Fits: Buddy 125/150 scooters, 139QMB and GY6 engines, and CVK or PWK carburetors

Compatibility

Fits:

• Buddy 125, 150 (CVK or PWK carburetor)
• 139QMB-based 50cc / 80cc engines (codes 139QMA, 139QMB, 1P39QMB, 1P39QMA-2, YN139QMB, JJ1P39QMB, 139FMA-2, BD1P39QMB, BN139QMB, 147QMD, other QMA and QMB models)
• 157QMJ-based 125cc / 150cc / 169cc engines (codes 157QMJ, 161QMK, 152QMI, 1P61QMK, YN1P57QMJ, 1P52FMI, 154FMI, JJ157QMJ, 1P57QMJ, BN157QMJ, BN161QMK-A, other QMJ, QMK and QMI models)
• Other engines with a QM or FM code when running a CVK or PWK carburetor

How to choose: Find the engine code on your motor and check it against the list above, and confirm you have a CVK or PWK carburetor. Dialing in the right jet often takes some trial and error.

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