M6 Carburetor Main Jet Set: 32 Sizes from 55 to 150 for Derotto PHBN and PHVA Carburettors

This comprehensive carburetor main jet set provides mechanics and tuning enthusiasts with precise control over fuel delivery in Derotto engines. Designed specifically for PHBN and PHVA carburettor models, the kit features brass M6 threaded nozzles covering 32 different orifice sizes from 55 to 150. Each jet corresponds to a specific measuring hole diameter, allowing for exact fuel mixture adjustments to optimize engine performance, address rich or lean running conditions, or adapt to modifications. Whether you're fine-tuning for better throttle response, correcting air-fuel ratios after intake or exhaust modifications, or simply maintaining optimal carburetion, this selection gives you the right tool for the job.

Features and Construction

The kit's value lies in its complete coverage of common jetting requirements and its specific compatibility with popular carburetor types. With sizes incrementally spanning from 55 to 150, users can make fine adjustments rather than being limited to a few common sizes.

Material and Build

The nozzles are manufactured from brass, a traditional material choice for carburetor jets due to its resistance to fuel corrosion and its ability to be precision-machined to consistent orifice diameters. The M6 thread specification ensures proper fitment in the designated main jet port of compatible carburettors. Each jet is stamped or marked with its size number, providing clear identification and preventing mix-ups during installation or when comparing different jets.

Size and Practical Fit

The product listing confirms compatibility with Derotto main jet PHBN and PHVA carburettors, narrowing its application to these specific models. The 32-size range (55, 58, 60, 62, 65, 68, 70, 72, 75, 78, 80, 82, 85, 88, 90, 92, 95, 98, 100, 102, 105, 108, 110, 112, 115, 120, 125, 130, 135, 140, 145, 150) offers a graduated scale for tuning. A larger number indicates a larger orifice and consequently a richer fuel mixture at wide-open throttle, while a smaller number provides a leaner mixture.

Uses and Placement

These jets are central to carburetor adjustment, directly affecting engine performance, fuel economy, and emissions. They are used in both repair scenarios, to replace worn or damaged jets, and in performance tuning to match fuel delivery to engine modifications.

Event or Professional Use

For professional mechanics or dedicated tuners, having access to this full range means being able to service and optimize a wide variety of Derotto engines without needing to source jets individually. It is particularly useful for dyno tuning sessions, where incremental jet changes are made between runs to plot the optimal air-fuel curve. It also serves as a practical parts inventory for workshops specializing in small engine or motorcycle repair.

Everyday Home Use

For the home mechanic working on a Derotto-powered scooter, moped, or other small engine vehicle, this kit simplifies the tuning process. Instead of guessing which single jet size to order, the user can purchase the kit and experiment safely within bounds to cure issues like poor idle, hesitation, or high fuel consumption. It turns a complex tuning task into a more manageable, trial-and-error-friendly process with all necessary components on hand.

Benefits and Buying Value

The primary benefit is the elimination of guesswork and multiple orders when dialing in a carburetor. Instead of purchasing jets one at a time, this set provides a systematic approach to finding the perfect size for your specific setup.

Reuse and Low Maintenance

Brass jets, when kept clean and free of debris, are durable components. A set like this represents a long-term investment in your tuning capability. Once purchased, the jets can be reused across different projects or saved for future needs. Their maintenance is straightforward: occasional cleaning with carburetor cleaner and compressed air to remove any varnish or blockage.

Why Choose This Product

This product stands out due to its confirmed compatibility with Derotto PHBN/PHVA carburettors and its exceptionally wide size range. Many jet kits offer only a handful of common sizes, but this 32-piece spectrum allows for much finer control. It is sold as a single nozzle in your chosen size, allowing you to buy exactly what you need or to build your own custom set over time by purchasing individual sizes as required.