NGK Iridium Spark Plug Kit for Royal Enfield UCE Twin-Spark 350 & 500 (BS3 / BS4) - BPR5EIX + CPR6EAIX-9S

The complete two-plug set for a UCE twin-spark service. Both plugs the engine needs, in one order, so there is no guessing which goes where.

Both are NGK Iridium IX with a fine-wire centre electrode, giving easier cold starts, a steadier idle and cleaner running from an engine that is fussy about ignition. Iridium holds its gap far longer than the nickel plugs it replaces.

Direct fit. Nothing to adjust.

What is in the kit

• 1 × BPR5EIX · the 14mm main plug
• 1 × CPR6EAIX-9S · the 10mm auxiliary plug

These replace the two plugs Royal Enfield specifies for this engine, the Bosch WR8DP (M14) and UR6DC (M10). Royal Enfield's own manual states plainly that two spark plugs are fitted, and lists them as two separate items at every service interval.

Find your bike

Royal Enfield UCE twin-spark 350 · BS3 & BS4

• Thunderbird 350 · Thunderbird 350X
• Classic 350 · Bullet 350 (Trials)
• Electra 350 BS3

Royal Enfield UCE twin-spark 500 · BS3

• Thunderbird 500 · Classic 500 · Bullet 500

Single-plug UCE models take the BPR5EIX on its own: the BS6 Classic 350 and Bullet 350, the BS4 500s and the Continental GT 535. The cast-iron Bullet takes the BR6HIX, and the newer J-series 350 from 2020 is a different engine again.

Specifications

• Part numbers · BPR5EIX + CPR6EAIX-9S
• Type · Iridium IX, fine wire
• Threads · 14mm main, 10mm auxiliary
• Gap · factory pre-set on both
• Sold as · complete two-plug kit

Fitting

Both arrive pre-gapped. Thread each in by hand first, then torque to your manual's figure. If you check a gap, move the outer electrode only.

Unsure which you need? Send us your bike and year and we will confirm before you order.