YGQ Carburetor Jet Kit for Mikuni VM/TM/RS/HSR — 30-Piece (20 Main #120-240, 10 Pilot 17.5-40) for Tuning

YGQ's 30-piece carburetor jet kit supplies a broad selection of main and pilot (slow) jets designed to tune Mikuni VM, TM, RS, HSR and other common carburetor families for cleaner throttle response and better-fit fueling.

This kit collects 20 large-round main jets and 10 pilot (slow) jets to help you dial in air/fuel mixtures across a wide range of engines and riding conditions. Each jet is sized to give tuners and home mechanics the options they need when rejetting after exhaust, intake, altitude changes, or performance modifications. The parts are aftermarket replacements compatible with many Mikuni models and classic Japanese motorcycle carburetors.

Which carburetors and bikes will these jets fit?

These jets are intended for a variety of Mikuni carburetor types — including VM, TM pumper, RS/RSF flat-slide, HSR/HSR new style and select BST/VM smoothbore racks — and for many vintage and modern Japanese bikes. The listing includes specific model ranges from Suzuki, Kawasaki and Yamaha, among others. Always cross-check your carburetor model and jet thread/type before ordering.

• Compatible Mikuni families: VM16/29/33, TM33/36/40 pumper, RS34/36/38/40, HSR42/45/48, BST40.
• Fits various Suzuki models (DR-Z125, GS series), Kawasaki Z and KZ series, Yamaha TTR125 and XS series.
• Included jets suit both round-slide and flat-slide carburetors with common thread sizes used by Mikuni.

What sizes are included and how do they help tuning?

The kit contains twenty main jets covering #120 up to #240 and ten pilot jets ranging from 17.5 to 40. This selection lets you make fine incremental adjustments to both the main (high-speed) circuit and the pilot (idle/low-speed) circuit for smooth throttle transition and correct fuel mixture at all RPMs. Having multiple sizes reduces guesswork and trips to the parts store while testing different setups.

• Main jet sizes: #120, 125, 130, 135, 140, 145, 150, 155, 160, 165, 170, 175, 180, 185, 190, 200, 210, 220, 230, 240.
• Pilot (slow) jet sizes: 17.5, 20, 22.5, 25, 27.5, 30, 32.5, 35, 37.5, 40.
• Wide range supports changes for altitude, aftermarket exhausts, air filters, and engine mods.

How do I use these jets during rejetting and maintenance?

Start with the factory-recommended jet sizes and change one circuit at a time while testing under real riding conditions. Use smaller steps when adjusting the pilot jet for idle and low throttle, and larger steps on the main jet for high-rpm tuning. Keep removed jets labeled and store spare jets in the kit to maintain a reference set for future retuning.

• Begin from stock jets, swap one size, and test ride under the load you normally use.
• Adjust pilot jets for crisp throttle response and idle stability; main jets affect top-end richness.
• Use an air/fuel plug chop or wideband if available to confirm mixture changes.

Who this kit is for: this 30-piece set suits home mechanics, track tuners, restorers of classic Japanese motorcycles, and riders who fit aftermarket filters or exhausts and need reliable jetting options. It’s especially useful for anyone working with Mikuni VM/TM/RS/HSR carburetors or owners of Suzuki DR-Z, various GS models, Kawasaki Z/KZ families, and Yamaha TTR/XS series who want to tune mixture across different conditions without repeatedly ordering individual jets.