Home / 4 Pack NGK Iridium IX 3521 Spark Plugs CR9EIX
4 Pack NGK Iridium IX 3521 Spark Plugs CR9EIX
$63.77
Free shipping on all orders.
Qty In Stock: 20
The NGK Iridium IX 3521 CR9EIX Spark Plug 4 Pack is designed to deliver dependable ignition, smooth engine performance, and long-lasting durability for motorcycles, ATVs, small engines, and powersports applications. Built with NGK's trusted Iridium IX engineering, these spark plugs provide reliable starts, efficient combustion, and consistent performance under demanding operating conditions.
Features & Benefits:
🔧 Includes 4 NGK CR9EIX Iridium IX spark plugs for convenient replacement
🔧 Iridium fine-wire center electrode helps support superior ignitability and longer service life
🔧 Durable construction resists wear, fouling, and high-temperature stress
🔧 Designed for consistent heat transfer and dependable ignition performance
Specifications:
Brand & Part Number: NGK 3521 (CR9EIX)
Quantity: 4 Pack
Product Type: Iridium IX Spark Plug
Application: Motorcycle, ATV, small engine, and powersports
Thread Size: 10mm
Reach: 19mm (3/4 in)
Hex Size: 16mm (5/8 in)
Heat Range: 9
Seat Type: Gasket
Resistor: Yes
Choose NGK CR9EIX Iridium IX spark plugs for trusted ignition performance, dependable durability, and smooth engine operation—order this 4 pack today!
Shipping Info
Free shipping on every US order. In-stock parts typically ship within 1 business day from Texas.
Returns
30-day returns on unused parts in original packaging. Wrong or defective items are replaced or refunded. See the return policy.
How do I confirm this part fits?
Match the brand and part number to your vehicle, or use the Parts Finder on the homepage. Contact us before ordering if you are unsure.
Are these parts new?
Yes. TXN Supply Co sells new parts from trusted OEM-quality brands — not remanufactured cores.
How fast will my order ship?
In-stock orders ship within 1 business day. Delivery time depends on your ZIP; most US addresses arrive in 2–5 business days.
What is your return policy?
Unused items can be returned within 30 days in original packaging. Customer-initiated returns may include a restocking fee and return shipping.
