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COVID-19 Update

As of the close of business Monday March 23rd, 2020, HMF Racing will be temporarily closing manufacturing and operations until May 1st as mandated by the State of Ohio to help slow the spread of the COVID-19 virus. We hope to resume normal work May 2nd, 2020. This is to protect the health and safety of all HMF staff and their families.

All orders that are currently in progress will be put on hold until operations resume. In Stock items are available to ship with negligible delays. New orders may still be placed on our website. Orders placed online will be charged and invoiced the next morning in order to reserve a place in the production queue. Delays in production in addition to the listed production time are possible depending on the volume of orders placed during this closure period.

From the HMF family to you:
Stay safe, stay healthy, and we look forward to helping you with your exhaust and equipment needs in the very near future.

Honda® TRX 400EX

The Honda TRX 400EX is available as a Slip-On, Full, and MX System in the Performance and Competition exhausts.  Each series Slip On exhaust picks up 10-15% more horse power and torque throughout the power curve.  The Full System adds another 5-10% more horse power while the MX system increases performance for high speed racing.  The mufflers will be roughly 4-6dB louder than the stock exhaust, but the Competition Inserts and HMF Quiet Core can reduce that 2-6dB.

Fits: (99-14) TRX 400EX, EX2, X, SporTrax

Fuel tuning is required learn more

Fuel Tuning is absolutely required when installing an HMF Exhaust on this machine. Failure to tune the engine can cause excessive damage to the exhaust system and engine, while voiding the warranty on your exhaust and possibly on your machine. (check with local dealer). See the tuning settings below for the proper fuel tuning solution on your machine.

Exhaust Systems

Honda® TRX 400EX ATV Accessories

Tuning

Recommended Tuning - Air Box Lid On
160 Keihin Hex, 42 Pilot (Slip On & Full System)

Recommended Tuning - Air Box Lid Off
175-180 Keihin Hex, 42 Pilot (Slip On & Full System)

HMF Basic Jet Kit Includes
152, 160, 165, 170, 175, 180 Keihin Hex, 42 Pilot Jet

Low Speed Fuel

Going down on the number scale will reduce low speed fuel. Going up on the number scale will increase low speed fuel.

Mid Range Fuel

Going down on the number scale will reduce mid range fuel. Going up on the number scale will increase mid range fuel.

High End Fuel

Going down on the number scale will reduce high end fuel. Going up on the number scale will increase high end fuel.

Green Lower Switch Point

Going down on the number scale will turn green mode on earlier. Going up on the number scale will turn green mode on later. These modes typically will not need adjusted from their base setting.

Yellow Lower Switch Point

Going down on the number scale will turn yellow mode on earlier. Going up on the number scale will turn yellow mode on later. These modes typically will not need adjusted from their base setting.

Red Lower Switch Point

Going down on the number scale will turn red mode on earlier. Going up on the number scale will turn red mode on later. These modes typically will not need adjusted from their base setting.

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