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Precision Raceworks

Precision Raceworks BMW Spark Plug Gap Tool/Gapper with Built-In Gap Opener & Feeler Gauge (12mm/14mm) for N54 N55 S55 - Fits M135i 135i 335i 435i 535i 740Li M2 M3 M4 X6 M

Precision Raceworks BMW Spark Plug Gap Tool/Gapper with Built-In Gap Opener & Feeler Gauge (12mm/14mm) for N54 N55 S55 - Fits M135i 135i 335i 435i 535i 740Li M2 M3 M4 X6 M

£51.51
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BMW Plug Gap Gauge and Opener with Feeler Blades - 12 mm and 14 mm - Precision Raceworks Part Number 601-0109

Achieve consistent ignition performance with this dedicated plug gap setting tool designed for BMW turbo straight six applications. The Precision Raceworks 601-0109 kit combines a precise gap opener with an included feeler gauge so you can adjust and verify the electrode gap quickly and accurately. Ideal for factory power or remapped setups where stable spark under load matters.

Key benefits

  • Purpose built gap setter for 12 mm and 14 mm plugs used across popular BMW turbo petrol engines
  • Integrated gap opener for controlled, repeatable adjustments without guesswork
  • Feeler blades included for precise measurement and consistent results car to car
  • Helps reduce high boost misfires and rough running by ensuring uniform plug gaps
  • Perfect for servicing, plug changes, coil diagnostics and tuning sessions
  • Compact and workshop friendly - great at home or in a professional bay

We use this tool in house at MJ Modifications and it just works. Fast to set up, easy to repeat across a full set and our customers are consistently pleased with the smoothness and reliability it delivers on road and track.

Engine and model coverage

Suits BMW platforms running 12 mm or 14 mm spark plugs commonly found on N54, N55 and S55 engines, including:

  • 1 Series E81 E82 E87 E88 135i N54 and N55, 135is
  • 2 Series F20 F21 M135i and M135i xDrive
  • 3 Series E90 E91 E92 E93 335i N54 and N55, 335xi, 335is
  • 3 Series F30 F31 F34 335i and xDrive, ActiveHybrid 3
  • 4 Series F32 F33 F36 435i
  • 5 Series E60 E61 and F10 535i, xDrive variants, ActiveHybrid 5, F07 5 Series GT 535i
  • 7 Series F01 740Li
  • M cars 1M E82, M2 F87 and M2 Competition, M3 F80, M4 F82 F83
  • X Series X3 F25 35i, X4 F26 35i, X5 E70 35i and F15 35i, X6 E71 35i and F16 sDrive35i and xDrive35i, X6 M E71
  • Z Series Z4 E89 35i and 35is

Not sure if your car uses 12 mm or 14 mm plugs or need guidance on target gaps for your tune. Get in touch and we will help.

How to use

  1. Select your target measurement using the included feeler gauge as specified by your tuner or service data.
  2. Place the plug in the tool and use the built in opener to adjust the ground electrode slowly and evenly.
  3. Confirm the clearance with the feeler blade. Repeat until the blade slides with light, even drag.
  4. Match all plugs to the same reading for consistent cylinder to cylinder performance.

Part number and manufacturer

Manufacturer: Precision Raceworks
Part number: 601-0109

Professional fitting and support

Prefer us to gap and install your plugs or want a health check on coils and ignition. MJ Modifications offers fitting and support at our Warwickshire workshop. Request a quote at info@mjmodifications.co.uk.

Why buy from MJ Modifications

  • BMW turbo specialists with hands on experience using this exact gap adjuster
  • Practical advice for N54, N55 and S55 ignition setups on stock and tuned cars
  • Friendly UK based support and quick dispatch

Search terms customers use

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