Main Jet #98 for SI Carbs for Scooters & Mopeds

Main Jet #98 for SI Carbs on Scooters and Mopeds

The Main Jet #98 is a key component in scooter and moped carburetors. It controls how much fuel reaches the engine, which affects how smoothly it runs and how it performs. Built to work with a range of vintage machines, particularly those using SI carburetors, this jet handles a central role in fuel delivery. It belongs to the range of carburetor jets for scooters and has a direct effect on engine efficiency and throttle response.

Getting to Know Jet Sizes

This jet has a cone-shaped design and sits in the lower part of the main jet setup. Available sizes run from 82 to 165, and many vintage Vespa scooters generally use jets in the 85 to 116 range. If your engine has been modified for more power, a larger jet may be needed to supply the extra fuel it draws.

Why Correct Jetting Matters

Finding the right jet size usually takes some testing. Changing the jet can bring better performance and improved fuel economy, so it is an important step in any tuning job. For more detailed jetting instructions, specialized references or step-by-step guides are worth looking at.

Specifications

• Size: 98
• Position: Main jet stack
• Fits: Dell'Orto/Spaco SI carburetors with a compatible SI main jet stack (20/15, 20/17, 20/20, 24/24)

Compatibility

Compatible with:

• Vespa vintage large frame: VNB, VBA, VBB, VNC 125 Super, VBC 150 Super, VNL GT/GTR, VLB Sprint, VLA GL150, VSD Rally 180, VSE Rally 200 (SI carburetor setup required)
• Vespa P/PX: VNX 125, VLX 150, VSX 200 E (SI carburetor setup required)
• Vespa VSB GS 160, VSC SS 180 (only with a compatible SI carburetor setup)
• Stella 150 2T (compatible SI carburetor setup only)

How to choose: Pick the size that suits your engine. A #98 is not necessarily the factory size for every vehicle on this list. Use it only as an SI main jet, not as an idle or air-corrector jet.

Shop more: Scooter Carburetors & Jets · Scooter Parts