Yamaha MT-03 mods & upgrades

The MT-03 is the R3 with a handlebar: the same 321 cc twin, frame and inverted fork, at $4,999. Most engine, chassis and brake parts are listed for both bikes, so the R3 catalog is the parts pool.

1. Tail tidy

   Fit a fender eliminator: Yamaha sells a genuine R3/MT-03 kit (1WD-F16E0-V0-00), Yoshimura lists the MT-03 for 2020–26, and TST lists 2020–24 kits plus separate 2025+ kits. Check the year first, because the tail changed for 2025.

   Tail Tidy & Billet

2. Sliders and case covers

   Fit frame sliders and engine covers. Puig lists Pro frame sliders for the MT-03 (2016+), TST lists MT-03 2020+ case protectors, and GB Racing lists R3/MT-03 covers for 2015–22 and 2023–26.

   Crash Protection

3. Slip-on

   Fit a slip-on for sound and weight. Akrapovič (2016–26), LeoVince's LV-10 (2015–26) and Two Brothers (2020–21) list one; Coffman's has a separate 2025–26 shorty. Akrapovič says its approved carbon slip-on needs no remap.

   Exhaust

4. Tank grips

   Stompgrip lists MT-03 2020–26 tank grips, a cheap fix for the wide tank cover.

   Clip-ons & Throttle

5. Springs and tires

   The fork is set softer than the R3's and the shock is preload-only, so fit springs for your weight at both ends. Then replace the OE tires with a modern sport tire in 110/70-17 and 140/70-17.

   SuspensionTires & Wheels

1. Tires

   Fit race or trackday tires in 110/70-17 and 140/70-17. This is the first step; the chassis is the R3's and responds to it.

   Tires & Wheels

2. Pads, braided line, fluid

   Fit sintered pads, a braided line and fresh fluid. The front is one 298 mm disc with a 2-piston caliper, and Cycle News' reviewer found it short on power.

   Brakes

3. Suspension: the R3 catalog

   Fit springs or cartridge internals and a better shock. Traxxion lists R3 fork springs, an AK-20 cartridge kit and YSS and Penske shocks, and Norton Racing sells an R3 adapter for a Ninja 650R shock (R3-listed; check MT-03 fit).

   Suspension

4. Gearing

   Stock is 14/43 on a 520 chain. Adding two or three rear teeth shortens the gearing for a racetrack; TST lists a captive chain adjuster for the R3 2015+ and MT-03 2020+.

   Drivetrain

5. Protection and levers

   Fit engine covers and, if your organization requires one, a lever guard. Norton Racing lists 3/4-length folding race levers for the R3 and MT-03; the 2025 clutch lever changed, so confirm the year.

   Crash ProtectionLevers

6. Flash and full system

   Woolich lists the MT-03 for 2015–24, and 2WDW sells an MT-03 flash and a separate 2025+ R3/MT-03 flash; both sell for closed-course use. It pays off only with a full system or de-cat pipe; skip it on a slip-on.

   TuneExhaust

• Overseas 2016–192016–2019

  The first 321 cc MT-03 was not sold in the US: the R3's engine and frame with a conventional 41 mm fork, like the 2015–18 R3. Marketplace listings for it are common, but fork, fender and front-end parts don't cross to the 2020+ US bike. Yamaha's 2006–14 MT-03 was a different bike, a 660 cc single.

• 2020 US launch2020–2024

  The MT-03 reached the US for 2020 as the naked R3: the same 321 cc twin and steel diamond frame, the R3's 37 mm inverted KYB fork with a softer spring and less compression damping, an LED headlight, an LCD dash and a bar 1.5 in taller and 0.7 in closer. $4,599 at launch. Two recalls cover 2020 bikes (rear reflector lens, certification-label VIN). Yamaha's 2024 US spec sheet lists the same fork, shock, brakes and seat height as the 2020 launch coverage.

• 2025 update2025+

  New tail section and taillight with subtle front-end refinements, an assist-and-slipper clutch with a reshaped clutch lever, a new LCD with Y-Connect phone notifications and a USB-A socket, a slimmer seat and side covers, and a wider passenger seat. Engine, frame, fork and brakes carry over, so tail, clutch-lever and dash parts split at 2025. Yamaha lists 2026 at $4,999 with the same specs.