Recommended Additional Upgrades
02
Uma Laser Iridium Spark Plug
Improve ignition with Uma Racing Laser Iridium Spark Plug.
The UMA Racing Throttle Body Kit (32mm) is the “Street Performance” entry in UMA’s high-flow induction lineup. While the 34mm version is geared toward big-bore racing builds, the 32mm bore is designed for riders who want improved throttle response and midrange torque on stock or lightly modified engines without sacrificing rideability.
It is a direct fit for the Yamaha 155cc VVA engine family, including the R15 V3/V4, MT-15, XSR 155, and FZS V2.
Key Features
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32mm Bore Diameter: An upgrade over the stock 30mm unit. This provides a measurable increase in airflow, which helps the engine breathe better at higher RPMs where the VVA (Variable Valve Actuation) kicks in.
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Precision Die-Cast Body: Made from a high-quality alloy that maintains its shape under high heat, ensuring there are no air leaks that could cause erratic idling.
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CNC Velocity Stack: Includes a machined aluminum air funnel that straightens air intake, reducing turbulence and increasing the speed of the air entering the engine.
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Dual Injector Support: Like its larger siblings, this 32mm body is dual-injector ready. This is a massive advantage if you plan to add a secondary injector for high-RPM fueling in the future.
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Variable Tuning Capability: The kit allows for fine-tuning of the idle and throttle positions, giving you more control over the engine’s behavior compared to the non-adjustable stock unit.
Performance Advantage: The “Mid-Range Specialist”
The 32mm kit is often preferred over the 34mm for daily street use because it maintains higher intake air velocity at lower RPMs.
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Better Low-End Torque: Because the bore isn’t “oversized,” the engine doesn’t lose low-end “grunt,” making it easier to pull away from traffic lights.
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Smoother Power Band: It provides a very linear power delivery that feels like a more “aggressive stock” setup.
Tuning Recommendation
Even though the 32mm is the smallest upgrade in the UMA kit lineup, it still alters the air-to-fuel ratio of your engine.
Expert Guide Note: To get the most out of this kit, you should pair it with a High-Flow Air Filter (like the UMA Dual Kit) and a Racing ECU (like the UMA M5). This allows you to increase the fuel delivery to match the extra air, preventing the engine from running “lean.”
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FAQs
Is 32MM better than 34MM for street use?
Yes, most riders prefer 32MM for better low-end and daily rideability.
Do I need ECU tuning?
Recommended for best results, especially with exhaust and filter upgrades.
Will this fit R15M?
Yes, this listing covers R15 V3 / V4 / M platform fitment.
