300EX Performance Carburetor for TRX300 4×4 – A Must-Have Upgrade

Upgrade your Honda TRX300 4×4 with this 300EX performance carburetor — a tried-and-true mod that brings sport quad throttle response to your workhorse. Designed for the more aggressive 300EX engine, this carb provides improved airflow, better throttle snap, and noticeable gains in overall power and responsiveness.

Perfect for riders looking to:

• Wake up a sluggish stock TRX300

• Pair with intake/exhaust mods

• Boost trail or recreational performance

Tuning Recommendations:
Jetting may vary depending on mods and elevation, but common baseline settings are:

• Main Jet: 128–135

• Pilot Jet: 38–42

• Needle Position: Middle clip

• Air/Fuel Screw: 2 to 2.5 turns out

Fine-tuning may be necessary to match your exact setup (aftermarket intake, exhaust, airbox mods, or altitude changes).

Note: This is a performance modification and is not a direct bolt-on replacement for stock TRX300 carbs without tuning.