NGK SPARK PLUGS CR9EIX 3521 Iridium IX Spark Plug 10 PACK

OVERVIEW

The NGK CR9EIX Iridium IX spark plug delivers dependable ignition reliability for high-performance motorcycles and snowmobiles. This 10 pack of precision engineered plugs features an ultra-fine iridium center electrode housed in an anti-corrosion plated steel shell, designed specifically to replace worn OEM units in demanding two-stroke and four-stroke platforms.

ENGINEERING & PERFORMANCE

The 1.1 millimeter iridium tip operates at roughly one quarter the diameter of a conventional nickel electrode, which significantly lowers the voltage required to bridge the gap during combustion. This reduction eases strain on the ignition coil and primary wiring, directly extending ignition system life while maintaining consistent hot firing under heavy loads. The hardened iridium alloy resists wear and maintains its precise gap over thousands of miles, while the enhanced corrosion resistant shell plating protects against moisture buildup and fuel vapor degradation. Built for direct cross reference compatibility, these plugs seat correctly and torque to standard specifications without modification.

KEY FEATURES

• NGK Iridium IX technology (CR9EIX / Item 3521)
• Ultra-fine 1.1mm iridium center electrode
• Reduces ignition voltage requirements to protect coils and wires
• Extended maintenance intervals through superior electrode durability
• Anti-corrosion plated steel shell resists fouling and oxidation
• Direct cross reference replacement for select factory plugs
• Precisely controlled heat range for stable combustion
• Economical 10 pack configuration for complete platform servicing

TECHNICAL SPECIFICATIONS

• Brand: NGK
• Part Name: Iridium IX Spark Plug CR9EIX
• Component Type: Spark Plug
• Core Material: Iridium center electrode, corrosion-resistant steel shell
• Supported Years: 1989–2020 (application dependent)
• Compatible Trims: Multiple motorcycle and snowmobile variants listed below

FITMENT

• 2019 Arctic Cat ZR 7000 Limited iACT w/137" Track
• 2019 Arctic Cat ZR 7000 w/137" Track
• 2019 Yamaha SR Viper LTX SE w/141" Track
• 2019 Arctic Cat Pantera 7000 XT Limited w/154" Track
• 2019 Yamaha SR Viper LTX SE w/137" Track
• 2019 Arctic Cat Bearcat 7000 XT w/154" Track
• 2019 Arctic Cat ZR 7000
• 2019 Arctic Cat Pantera 7000 Limited w/146" Track
• 2017 Harley-Davidson Street Glide Special FLHXS
• 2017 Harley-Davidson Freewheeler FLRT
• 2017 Harley-Davidson Electra Glide Ultra Limited FLHTK
• 2017 Harley-Davidson Tri Glide Ultra Classic FLHTCUTG
• 2017 Harley-Davidson Road Glide Special FLTRXS
• 2017 Harley-Davidson Electra Glide Ultra Limited Low FLHTKL
• 2017 Harley-Davidson Street Glide EFI FLHX
• 2017 Harley-Davidson Road King EFI FLHR
• 2017 Harley-Davidson Road Glide Custom FLTRX
• 2017 Harley-Davidson Road Glide Ultra FLTRU
• 2017 Harley-Davidson Electra Glide Ultra Classic EFI FLHTCUI
• 2015-2019 Aprilia Tuono V4 1100 Factory
• 2015-2019 Aprilia Tuono V4 1100 RR
• 2015-2017 Harley-Davidson Street 750 XG
• 2015-2017 Harley-Davidson Street 500 XG
• 2014-2017, 2019 KTM 450 Rally Factory Replica
• 2013-2017 Husqvarna TE 450
• 2013-2017 Husaberg FE 250
• 2011-2016 Aprilia Tuono 1000 R RSV V4 APRC ABS
• 2011-2016 Aprilia Dorsoduro 1200
• 2011-2016 Husqvarna TE 449
• 2011-2016 Husqvarna TE 511
• 2011-2015 Husqvarna TC 449
• 2011-2014 Aprilia Tuono V4 R
• 2011-2012 Husqvarna SMR 511
• 2011-2012 Husqvarna SM 449 R
• 2011 Husqvarna SM 511 R
• 2011 KTM 250 XCF-W 4-Stroke
• 2010-2020 KTM 250 EXC-F Six Days
• 2010-2018 KTM 250 XCF-W
• 2010-2016 KTM 250 XCF-W Champions Edition
• 2010-2015 Yamaha Phazer 500
• 2010-2014 Yamaha Venture 500 Lite
• 2010, 2013-2018 Yamaha Venture 500 MP
• 2010 Yamaha Phazer 500 Mountain Lite
• 2010 Aprilia RSV4 Factory
• 2009-2019 KTM 450 SX
• 2009-2015 KTM 505 SX
• 2009-2011 Husqvarna TE 250
• 2009-2011 Husqvarna TC 250
• 2009-2010 Buell 1125 CR
• 2009-2010 Husqvarna TE 310
• 2009 MV Agusta Brutale 1078 RR
• 2009 MV Agusta F4 1078 RR
• 2009 Yamaha FZ1
• 2008-2013 BMW G 450 X
• 2008-2011 Husqvarna SMR 450 R
• 2008-2010 Buell 1125 R
• 2008 Benelli Tre-K 1130
• 2008 Benelli TNT 1130
• 2007-2019 KTM 505 SX-F
• 2007-2011 KTM 450 SX-F
• 2007-2010 KTM 250 EXF
• 2006-2012 KTM 250 SX-F
• 2006-2008 Triumph Daytona 675
• 2006-2008 MV Agusta Brutale 910 R
• 2006-2007 Ducati ST3 992 S
• 2006, 2008 MV Agusta Brutale 910 S
• 2005-2020 KTM 250 SX
• 2005-2016 KTM 450 SMR
• 2005-2007 Ducati ST3 992
• 2005 Triumph Daytona 650
• 2004-2005 Kawasaki Ninja ZX-12R
• 2004-2005 Ducati ST3
• 2004 Yamaha RX Warrior 1000
• 2003-2004 Yamaha RX-1 1000
• 2003-2004 Yamaha RX-1 ER 1000
• 2003-2004 Kawasaki ZX-6 ZZR 600
• 2003-2004 Yamaha Apex Mountain 1000
• 2003 Kawasaki Ninja ZX-6 RR
• 2002-2006 Triumph Daytona 955 I
• 2002-2005 Kawasaki ZX-12C ZZ-R1200
• 2001-2007 Suzuki DR-Z 250
• 2001-2005 Kawasaki ZRX 1200 R
• 2001-2005 Suzuki GSX-R 1000
• 2001-2002 Suzuki SV 650 S
• 1999-2007 Suzuki GSX 1300 R Hayabusa
• 1999-2002 Suzuki SV 650
• 1998-2002 Suzuki TL 1000 R
• 1997-2007 Suzuki GSX-R 600
• 1997-2006 Yamaha TT-R 250
• 1997 Suzuki VZ 800 Marauder
• 1996-2007 Suzuki GSX-R 750
• 1996-1997 Kawasaki ZX-7 RR Ninja
• 1995-1997 Kawasaki Ninja ZX-6R
• 1994-2007 Yamaha YZF 600 R
• 1994-1997 Suzuki RF 900 R
• 1994-1996 Suzuki RF 600 R
• 1993-2002 Kawasaki ZX 600E Ninja
• 1993-1998 Suzuki GSX-R 1100
• 1993-1998 Yamaha YZF 750 R
• 1993-1994 Kawasaki ZR 1100 A
• 1993, 1995-1998 Suzuki GSX-R 1100 W
• 1990-1996 Kawasaki Ninja ZX-11
• 1989-1995 Kawasaki ZX-7 Ninja
• 1989-1990 Yamaha FZR 600

WHY RIDERS CHOOSE THIS

Riders upgrade to this NGK Iridium IX plug because the microscopic tip fires more consistently under high load, eliminating hesitation and restoring crisp throttle response across the rev range. The extreme durability of iridium keeps the gap precise mile after mile, which translates to fewer replacements and sustained performance between services. By lowering the electrical demand needed to create a spark, the plug reduces stress on aging magnetos and stator systems, protecting costly underlying components. Engineered to match OEM dimensions and heat characteristics, it drops directly into compatible motorcycle and snowmobile cylinders without tuning modifications or custom mounting adjustments.