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Air and Fuel› Carburetors and Components

Mikuni

Flatslide Pumper Carburetor

$390.00 $389.95 Save $0.05

SKU: TM42-6

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Special Order
Ships in 4–6 weeks
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$100 Minimum Order
30 Days Return
INSTALL DIFFICULTY
DIY PRO SHOP

Moderate — 2–4 hours

Overview

The Mikuni TM42-6 carburetor is a flatslide pumper designed for performance engine builders. It flows 17 CFM more than the TM40-6 and features a roller-bearing slide, contributing to improved starting, rideability, and power. This carburetor is suitable for custom and race applications.
Show original supplier description
The Mikuni TM42-6 HSR carburetor is a high-performance unit designed for custom and race applications. It offers a significant flow increase of 17 CFM over the TM40-6, thanks to its flatslide pumper design and upgraded roller-bearing slide. This results in improved throttle response, smoother acceleration, and increased horsepower and torque. Buyers can expect to say goodbye to hard starting, hesitations, and flat spots. It utilizes the stock choke cable from a CV-type carburetor, with choke cables sold separately. For specific applications like the Suzuki DR650, it can be correctly sized and fitted using an included air-box adapter, though the motorcycle's airbox may need modification for optimal airflow. Pre-1996 models may require additional spacers and boot modifications due to starter motor clearance issues. The TM42-6 comes fully re-jetted for the application with spare main jets for fine-tuning. It is noted that climate, altitude, fuel density, and engine modifications like cam, exhaust, or cylinder head porting can affect final tuning. Dyno tests have shown performance improvements of up to and over 25% when fitted to OEM-carbureted engines.
Vehicle Symptoms
  • Engine hesitates on acceleration
  • Hard starting when cold
  • Flat spots during throttle opening
  • Poor throttle response at low RPM
  • Engine stumbles under load
Relevant Conversations
  • Mikuni TM42-6 carburetor for DR650 upgrade
  • Flatslide pumper carb vs CV carb performance
  • TM42-6 tuning tips for better throttle response
  • Hard starting after carb swap Mikuni fix
  • Mikuni TM42-6 vs TM40-6 CFM difference
  • How to install Mikuni TM42-6 on Suzuki DR650
  • Carburetor hesitation at low RPM solution
  • Best performance carburetor for custom bike build
  • Mikuni TM42-6 jetting guide for altitude
  • Upgrade carb for more horsepower and torque

Product descriptions are provided by our supplier partners and may not always be perfectly accurate. Not sure this fits? or call (760) 282-4645 and we’ll verify before you order.

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Specifications

BrandMikuni
Part NumberTM42-6
CategoryAir and Fuel
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(760) 282-4645 hello@motormia.co

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Built for enthusiasts. Every order is backed by our 30 day return window on eligible items. Unused and uninstalled products may be returned with approved RMA and no restocking fees when received in new condition. Orders placed through the MOTORMIA app with a complete build qualify for our Fitment Guarantee — free return shipping if the part doesn’t fit your exact setup. The guarantee covers fit only; installation must follow manufacturer instructions, and we recommend a qualified shop for parts marked Difficulty 4–5.

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Shipping

Orders are processed in 1–3 business days. In stock parts ship promptly from our partner network. Special-order items either aren’t currently stocked or are built to your spec — expect 4–6 weeks. If a part goes on backorder while your order is in the queue, we’ll reach out and work through discounted alternatives together.

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