Product images and videos 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.

Air and Fuel› Carburetors and Components

Mikuni

VM/TM/TMX Series Hex Main Jet, Size 170

Name: VM/TM/TMX Series Hex Main Jet, Size 170
Brand: Mikuni
SKU: 4/042-170

$31.61

SKU: 4/042-170

Free Shipping over $200

$100 Minimum Order

Non-Returnable Item

DIY PRO SHOP

Beginner — under 30 min

Description

The Mikuni 4/042-170 is a genuine Mikuni large hex main jet, specifically sized at 170 for fine-tuning Mikuni VM, TM, and TMX carburetors. This brass jet measures 11.5 mm in total length with a 5.2 mm thread diameter and a 5.25 x 0.9 thread pitch, ensuring precise fuel mixture control for optimal engine performance. These main jets are crucial components for carburetor tuning, allowing users to adjust the fuel-air mixture to match engine modifications, altitude changes, or specific riding conditions. Mikuni offers a wide range of jet sizes, from 50 to 720, to accommodate various tuning needs. This particular jet is essential for achieving the correct fuel delivery in compatible Mikuni carburetor systems. The Mikuni 4/042-170 is sold as a pair and includes no instructions. Buyers are advised to verify the dimensions of their existing jet to ensure compatibility, as Mikuni's fitment guides may not always be 100% accurate due to various factors. If unsure, it is recommended to consult with a professional or provide a picture of the removed jet for identification assistance.

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.

Fitment

Fitment Guaranteed

Don’t gamble
on fit.

Log your build in the MOTORMIA app and we’ll guarantee this part fits your exact setup — or your money back, return shipping covered.

Available on iOS & Android

Specifications

Brand	Mikuni
Part Number	4/042-170
Category	Air and Fuel

5,000+ Trusted brands

1M+ Enthusiasts

5M+ Parts sold

(760) 282-4645 hello@motormia.co

Buy with Confidence

Returns & Fitment

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.

View Full Return Policy

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.

Free shipping over $200 in the continental US. Alaska, Hawaii, U.S. territories (Puerto Rico, U.S. Virgin Islands, Guam, American Samoa, and the Northern Mariana Islands), and international orders carry surcharges — most appear at checkout. Some exceptions (LTL freight, or suppliers who quote freight only after we place the order) won’t. In those cases we’ll reach out with the exact charge before your order moves forward.

View Full Shipping Policy