YGQ Carburetor Jet Kit for Mikuni VM/TM/HSR Carburetors — 42-Piece Tuning Set with Main & Pilot Jets

This YGQ Carburetor Jet Kit gathers commonly used main jets, pilot jets and slow jets into one organized set so you can quickly address fueling needs without hunting down individual parts. The selection covers both large-round and large-hex main jets, plus pilot/small jets sized for multiple Mikuni family carburetors. It’s designed for owners, mechanics and tuners who service 2-stroke and 4-stroke street bikes, offroad machines and ATVs built with Mikuni-style carbs.

Which carburetors and vehicles will this YGQ kit work with?

The kit supports a broad range of Mikuni carburetors including VM, TM, HSR and HS flat-slide styles as well as many smoothbore and round-slide models. It’s suitable for common Japanese makes and many aftermarket setups that accept standard Mikuni jets.

• Compatible models: VM16–VM44, VM29/33 smoothbore; TM24–TMX series; HSR42/45/48; RS34–RS40 rack types.
• Needle jet compatibility: 171, 188, 196 (with large round), and 568, 640, 723 series.
• Fits many Honda, Suzuki, Kawasaki, Yamaha and Polaris carbureted bikes and ATVs.

How does this kit help when tuning or repairing a carburetor?

Having a wide spread of jet sizes on hand makes it easier to identify the correct jetting for altitude, temperature, fuel type or engine modifications. Instead of trial-and-error ordering, you can swap jets on the bench or track and observe differences immediately.

• Large-round and large-hex main jets provide fine incremental changes from lean to rich.
• Pilot/slow jet range addresses idle and low-throttle response adjustments.
• Allows stepwise tuning for acceleration, cruise and top-end performance without downtime.

What sizes are included and why do they matter?

The kit contains a comprehensive spread of sizes so you can tune across operating ranges. Main jets cover small to very large orifices while pilot jets fine-tune low-speed fuel delivery; matching the right size is critical to avoid stalling, hesitation or excessive fuel use.

• Main jets (large round): sizes include 90 through 190 in progressive steps for precise top-end tuning.
• Main jets (large hex): include 130 up to 280 for higher-flow applications and aftermarket slides.
• Pilot/slow jets: TM pilot slow 17.5–40 and VM pilot slow 25–60 to dial idle and partial-throttle settings.

How should I use these jets safely and effectively?

Start with the factory-recommended jet and change one variable at a time, logging the engine response after short test runs. Use proper tools to avoid rounding jet heads and keep jets organized to prevent cross-contamination; always re-check for leaks after reassembly.

• Swap one jet at a time and test ride in consistent conditions.
• Use the correct screwdriver or wrench to avoid damaging jet slots or hex heads.
• Label and store leftover jets to create a reference map of what improved or harmed performance.

Who is this for: This YGQ 42-piece jet kit is aimed at DIY mechanics, performance tuners and professional shops that work on Mikuni-equipped motorcycles and ATVs. It’s useful for riders adapting to altitude or fuel changes, those fitting aftermarket airboxes or exhausts, and anyone who wants a one-box solution to fuel-system jetting across a wide range of Mikuni carburetor models.