MRELC Air Filter Adapter & Jet Kit for Predator/GX 301–420cc Engines — Blue, 11 Jets + Gaskets

MRELC's blue Air Filter Adapter Jet Kit is a complete upgrade pack that fits Predator and GX series 300–420cc OHV engines, supplying an air filter, adapter pieces, two gasket sets, 11 main jets and related installation hardware for easier tuning and improved intake protection.

This kit is built for small-engine users who want a single package to handle intake protection and basic jetting for mini bikes, go-karts, generators, pressure washers, lawnmowers and similar equipment powered by Predator 301cc/420cc or Honda GX340/GX390 compatible engines. It groups commonly needed parts—filter, adapter, spark plug, fuel filter, multiple jets and gaskets—so you can avoid multiple purchases and tune carburetion without searching for individual components.

What exactly comes in the kit and why is it useful?

The MRELC kit combines consumables and tuning hardware to make routine maintenance and carburetor tuning faster. It includes parts to replace worn gaskets, swap jets for different fuel/altitude conditions, and add an aftermarket filter and adapter for improved filtration and flow.

• 1 air filter and 1 adapter kit for aftermarket intake fitment
• 11 main jets (#0.74–#0.94 range) to tune fuel mixture
• Spark plug, fuel filter, insulation and multiple gaskets for install
• Hardware: 2 nuts and 2 screws supplied for secure mounting

How does the jet selection help when tuning carburetion?

Having an assortment of main jets lets you fine-tune the engine mixture for different loads, elevations, fuel grades or modifications. Swapping jets adjusts the main fuel circuit, helping you reduce running lean or rich conditions during testing.

• 11 discrete jet sizes from 0.74 to 0.94 for incremental tuning
• Allows on-site adjustments without ordering additional parts
• Simplifies troubleshooting of power, throttle response and fuel economy

Will this kit fit my Predator or Honda GX engine model?

The adapter and gasket set are designed to be compatible with Predator 301cc and 420cc engines and popular Honda clones including GX340/GX390 and similar 389cc OHV engines. Two types of carburetor gaskets and exhaust gaskets are included to accommodate common variations in mounting surfaces.

• Compatible models listed: Predator 301cc/420cc, GX340, GX390, 389cc variants
• Two carburetor and two exhaust gaskets provided for fit flexibility
• Works with mini bikes, go-karts, generators, pumps and lawn equipment

What tools and steps are needed to install and tune this kit?

Installation requires basic hand tools such as wrenches and screwdrivers, a socket set for spark plug removal, and patience to test different jets. After fitting the adapter and filter, start with the stock jet closest to your original and make small jet changes while observing throttle response and exhaust color to refine mixture.

• Standard hand tools and safety gear; no special fabrication needed
• Start with original jet size, then test progressively richer or leaner jets
• Observe idle, acceleration and plug color when assessing changes

Who is this for: This MRELC kit is aimed at DIY small-engine owners, hobbyists and repair shops that service mini bikes, go-karts, portable generators, pressure washers, lawn equipment and light marine or off-road craft with Predator or GX-series clone engines. It’s useful for anyone who wants one consolidated package to replace worn parts, adapt an aftermarket air filter and experiment with carburetor jetting without multiple orders.