--- product_id: 280880862 title: "G4074 Colortune Single Plug Kit 14mm" brand: "gunson" price: "€ 743.23" currency: EUR in_stock: true reviews_count: 5 category: "Gunson" url: https://www.desertcart.pt/products/280880862-g4074-colortune-single-plug-kit-14mm store_origin: PT region: Portugal --- # 14mm universal fit plug Hexagonal adaptor included UK-made precision tool G4074 Colortune Single Plug Kit 14mm **Brand:** gunson **Price:** € 743.23 **Availability:** ✅ In Stock ## Summary > ⚡ See the spark, own the tune — master your engine’s heartbeat! ## Quick Answers - **What is this?** G4074 Colortune Single Plug Kit 14mm by gunson - **How much does it cost?** € 743.23 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.pt](https://www.desertcart.pt/products/280880862-g4074-colortune-single-plug-kit-14mm) ## Best For - gunson enthusiasts ## Why This Product - Trusted gunson brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Modular Adaptability:** Extra adaptors available for diverse engine types - • **Universal Compatibility:** Fits most petrol engines with M14 threaded plugs - • **Trusted British Craftsmanship:** Manufactured in the UK with ethical sourcing - • **Effortless DIY Engine Optimization:** Clear instructions make professional tuning accessible - • **Precision Tuning at Your Fingertips:** Visualize combustion for perfect carburettor adjustments ## Overview The G4074 Colortune Single Plug Kit 14mm is a precision automotive tool designed for petrol and LPG engines, enabling real-time visual tuning of carburettor mixtures through a unique color-based combustion chamber inspection. Compatible with most vehicles using M14 threaded plugs, it includes a hexagonal adaptor and detailed instructions, with additional adaptors available for broader fitment. Proudly manufactured in the UK by Gunson, this kit combines expert craftsmanship with user-friendly design, making it the go-to choice for professional and classic vehicle technicians aiming for optimal engine performance. ## Description The Tune-up plug for Petrol/LPG 2 and 4 stroke engines with single, twin or multiple carburettors or fuel injection systems.The original and best tool for seeing what's happening inside the combustion chamber of the petrol engine. It allows you to see the combustion and to adjust the mixture by colour. Fits most petrol engines in standard form with additional adaptors available for vehicles with alternative sized spark plugs. A British tool company based in Warwickshire, United Kingdom. Gunson Tools draws on years of experience to introduce quality products which offer real value for money. All our products are responsibly sourced both from trusted ethical partners across the world PLUS (uniquely as an automotive tool brand) our own manufacturing base in the UK. Trusted quality products like Eezi-Bleed, ColourTune, Carbalancer and Eezi-lap are just a few names within the range. Combining our British manufacturing, our years of experience and vast expertise in the automotive sector helps us achieve our aim of bringing high quality tool solutions first to market and being No.1 choice for the Classic vehicle technician Review: Kit per controllo della carburazione - Buon prodotto per fare la carburazione. Ti permette di effettuare le regolazioni necessarie e capire bene o male in che condizioni è il motore. Facile nell'utilizzo. Io l'ho usato per carburare una 500 d'epoca. Review: Matériel révolutionnaire efficacité et bon marché. - Article vraiment pratique le réglage de la richesse carburation est au top, bon réglage = économie , facile d'emploi. Des vidéos concernant cette bougie est disponible sur youtube, bien pratique. ## Features - Kit includes: 14mm Short reach plug and Hexagonal adaptor - Colortune will fit most vehicles fitted with M14 threaded plugs - Kit complete with instructions - Extra adaptor sizes available separately, please see Gunson Part Nos G4055E (18mm), G4055D (14mm long reach), G4055C (14mm tapered seat), G4055B (12mm), G4055A (10mm) - The complete Colortune kit is also available with the following adaptors G4171 (with 12mm Colortune Plug), G4172 (with 10mm Colortune Plug) - Automotive Tool ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B0012MB4VE | | Automotive Fit Type | Universal Fit | | Brand | GUNSON | | Brand Name | GUNSON | | Compatible with Vehicle Type | Car | | Customer Reviews | 4.6 out of 5 stars 567 Reviews | | Global Trade Identification Number | 05018341740740 | | Included Components | 1 x Gunson Colortune 14 mm Kit Colortune Spark Plug Carburettor Mixture Tool | | Item Type Name | Gunson Colortune 14 mm Kit Colortune Spark Plug Carburettor Mixture Tool | | Item Weight | 0.15 Kilograms | | Manufacturer | Tool Connection (EU) | | Manufacturer Part Number | G4074 | | Model Number | G4074 | | Number of Items | 1 | | Thread Size | 14 millimeters | | Thread size | 14 millimeters | | Top Material Type | Nickel | | Top material type | Nickel | | Unit Count | 1.0 Count | | Vehicle service type | Car | ## Product Details - **Brand:** GUNSON - **Global Trade Identification Number:** 05018341740740 - **Number of Items:** 1 - **Top material type:** Nickel - **Vehicle service type:** Car ## Images ![G4074 Colortune Single Plug Kit 14mm - Image 1](https://m.media-amazon.com/images/I/710aUHECQJL.jpg) ## Questions & Answers **Q: what size adaptor do i need for spark plug autolite AP63 ?** A: It would be a good idea if you supplied the thread size on the spark plug you need info on, if you did that I could answer your question. **Q: Using a digital caliper, i measured the threaded portion of the spark plug and got a reading of 13.80mm. do i use the 14mm size colortune kit?** A: I would have to say yes you are correct, but I better add that just in case it is not you should check the thread pitch with guages or your caliper. Coarse thread is 2mm pitch and fine is 1.5mm fine. If you need any more info I'll check mine **Q: Will this tool work on a 72 Porsche engine. Or do I need adapters** A: I used it for 25 years on a '71 VW Super Beetle with the standard 1600 engine. It works like a charm. Mine was bought in the 80s from an adv. in Hot VWs. I still have the shipping bag with the nice black box. 'Never let me down. **Q: Will this work for a 70 gmc jimmy strait 6 2barrel carb , thanks.** A: I use this on my Mopar V8 440 from a '68 Chrysler 300. The 14mm thread. i recommend loosening up the plugs when the engine is cold and then (anti-seize) them back in not too tight. You could do all 8, but, for me, I am fine with just two on each side of my split plenum intake. ( If you have a split plenum design, check your runners on your intake so that you are really reading two from each carb side. Pretty funny if you happen to pick all four from the same carb circuit! For example, on RB engines, 3 and 5, 1 and 7, or 4 and 6, 1 and 8 are matched sides for a 4-barrel. So, 1 and 3, or, 2 and 4 would work fine.) Keep in mind the hot exhaust manifold/headers, so, pick the plugs you can get in without burning your fingers and heating up your plastic pipe (Gunson). After your engine is warmed up and you have done your vacuum or rev range or even AFR idle, etc., switch out the plug for the Gunson. If you can, wrap the plastic in the 1" DEI or similar heatshield. I used the Firesleeve. This will protect the flimsy black plastic. And, when done - don't take too long running the engine - take off the plastic parts and plug. Don't let heat soak kill your piece. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Kit per controllo della carburazione *by A***I on 15 April 2021* Buon prodotto per fare la carburazione. Ti permette di effettuare le regolazioni necessarie e capire bene o male in che condizioni è il motore. Facile nell'utilizzo. Io l'ho usato per carburare una 500 d'epoca. ### ⭐⭐⭐⭐⭐ Matériel révolutionnaire efficacité et bon marché. *by N***S on 27 October 2019* Article vraiment pratique le réglage de la richesse carburation est au top, bon réglage = économie , facile d'emploi. Des vidéos concernant cette bougie est disponible sur youtube, bien pratique. ### ⭐⭐⭐⭐⭐ Simple to use and accurate enough to get you going. Takes some of the Voodoo out of carb tuning :) *by S***I on 1 October 2015* I bought this because as a novice, after doing online research, I was feeling somewhat intimidated about tuning the carbs on my MGB roadster and I thought that this would provide me with an "easy" solution. And it did :) It seems that it is a bit of a "Marmite" product that you either hate or love. More experienced vintage car enthusiasts claim that it is inaccurate and unnecessary while other, probably less experienced owners, love it for its simplicity. I am a believer. It is incredibly easy to use and allowed me to tune my carbs to a significantly better state quickly and without stress. As a side benefit, it also provides you with the pretty cool opportunity to actually see the bang going on inside your engine! :) Remember that if you have a multi-carb engine, you will need to use this on one cylinder being fed by EACH of the carbs One caveat. The colortune is only an indication of fuel/air mixture combustion and therefore, in my opinion, does not replace a full carb tuning an balancing process. It does however give you the opportunity to easily get a close approximation to improve your ignition burn and running. In my case it also removed the vooodoo factor and made me more confident to then learn to fully tune the carbs on my car. ## Frequently Bought Together - GUNSON G4074 Colortune Single Plug Kit 14mm - Gunson G4055B Adaptor Kit 12 mm --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.pt/products/280880862-g4074-colortune-single-plug-kit-14mm](https://www.desertcart.pt/products/280880862-g4074-colortune-single-plug-kit-14mm) --- *Product available on Desertcart Portugal* *Store origin: PT* *Last updated: 2026-07-14*