Arrow 51003MI Stainless Steel Racing Collector - Yamaha YZF-R 125 (2008-2013)

Arrow Racing Header 51003MI – Yamaha YZF-R 125 (2008-2013)

The Arrow 51003MI stainless steel racing header is the high-performance header system designed for the Yamaha YZF-R 125 (2008-2013). Entirely made in Italy by Arrow Special Parts, this racing header replaces the original header and catalytic converter, unleashing the full potential of the Yamaha single-cylinder engine: +1.5 HP and +0.49 Nm with a weight saving of 3.2 kg compared to the stock exhaust.

✓ Strengths

• ✓ +1.5 HP power – from 12 HP stock to 13.5 HP (+12.5% increase)
• ✓ +0.49 Nm torque – from 10.59 Nm to 11.08 Nm for a quicker response
• ✓ -3.2 kg weight – significant lightening for a 125cc
• ✓ High-quality stainless steel – corrosion and high-temperature resistance
• ✓ 40 mm outlet diameter – optimized gas flow for the 125 single-cylinder
• ✓ Made in Italy – designed and produced by Arrow Special Parts in San Giustino (PG)

Technical Features

🔧 Specifications

Complete racing header in stainless steel. Outlet diameter 40 mm. Total weight 0.6 – 0.8 kg. Without DB Killer, without Lambda sensor, without CO sensor. This header is NOT road legal: it is a racing product intended exclusively for closed-circuit competitions or track use.

⚡ Verified Performance

Wheel measurements on a dyno (source: Arrow Special Parts):

• Stock power: 12.00 HP at 9,300 rpm → With Arrow: 13.5 HP at 9,300 rpm (+1.5 HP)
• Stock torque: 10.59 Nm at 7,800 rpm → With Arrow: 11.08 Nm at 7,800 rpm (+0.49 Nm)
• Stock exhaust weight: 5.50 kg → With Arrow: -3.20 kg saving
• Noise: 86 dB stock → 88 dB with Arrow (+2 dB)

🔗 Arrow Silencer Compatibility

This racing header is designed to work with the following Arrow silencers for Yamaha YZF-R 125:

• 51503AON – Street Thunder Aluminium Dark
• 51503AO – Street Thunder Aluminium

The silencer is sold separately. For those who need road homologation, Arrow also produces the Euro 3 approved catalytic header kit with code 51003KZ (sold separately in our store).

🏍️ Vehicle Compatibility

• Yamaha YZF-R 125 – year 2008
• Yamaha YZF-R 125 – year 2009
• Yamaha YZF-R 125 – year 2010
• Yamaha YZF-R 125 – year 2011
• Yamaha YZF-R 125 – year 2012
• Yamaha YZF-R 125 – year 2013

Please note: this header is specific for the YZF-R 125 years 2008-2013. For 2014 and later versions, Arrow produces dedicated headers with different codes. Please check the exact year of your motorcycle before purchase.

Who It's Perfect For

The Arrow 51003MI racing header is the ideal choice for those who use the Yamaha YZF-R 125 on the track, for track days, one-make races or trophies and wish to extract maximum performance from the 125cc single-cylinder. Perfect for young riders and enthusiasts who want an aggressive racing sound and a concrete gain in power and torque, with significant weight reduction for the motorcycle.

Warranty and Quality

Original product by Arrow Special Parts, Italian excellence in motorcycle exhaust systems since 1985. Sold by Moon Bike S.r.l., authorized dealer based in Cercola (NA). Fast and secure shipping throughout Italy and worldwide.

🛒 Order the Arrow 51003MI racing header now and unleash the power of your R125!