Idle Jet (50/120) for SI Carbs for Scooters & Mopeds
ITEM# TT-26200
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Description
Idle Jet for SI Carbs in Scooters and Mopeds
The 50/120 Idle Jet is made for SI carburetors found on a range of scooters and mopeds. It controls the fuel and air blend across the lower third of the throttle travel. As one of the scooter carburetors & jets available, it has a noticeable effect on how quickly the machine picks up speed. Choosing the right size helps avoid hesitation during acceleration and keeps throttle response smooth.
How the Idle Jet Works
This smaller jet sits beside the main jet stack and meters fuel and air when the throttle is only partly open. It also works alongside the main jet to control the mid-throttle range. An idle jet that doesn't match the bore specification can cause running problems, so sizing by bore is important.
Reading Jet Sizes
Each idle jet is marked with two numbers. The first is the fuel bore, and the second is the air bore. A 50/120 passes less air than a 50/140, which produces a richer mixture. Certain vintage Vespas use plugged idle jets, meaning they have no air hole, and these come in set sizes.
Specifications
- Size: 50/120
- Position: Beside the main jet stack
- Fits: SI carburetors on scooters and mopeds, idle jet size 50/120
Fitment
How to choose: Check the marking on your existing idle jet. This listing is for 50/120, where the first number is the fuel bore and the second is the air bore.
Shop more: Scooter Carburetors & Jets · Scooter Parts
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