{"product_id":"dayuan-petrol-engine-compression-tester-kit-blue-case-3-dual-scale-gauge-adapters","title":"DAYUAN Petrol Engine Compression Tester Kit — Blue Case, 3\" Dual-Scale Gauge \u0026 Adapters","description":"\u003cp\u003e\u003cstrong\u003eDAYUAN Professional Petrol Engine Compression Tester Kit is a complete diagnostic set that measures cylinder compression across a wide range of petrol engines using a 3\" dual-scale gauge and multiple adapters in a durable blue case.\u003c\/strong\u003e\u003c\/p\u003e\n\n\u003cp\u003eThis compression tester kit gives mechanics and DIYers the tools to check engine health quickly and accurately. The set includes a 3\" gauge with dual color markings (0–300 psi \/ 0–20 bar), four threaded fittings with O-rings, two spark plug adapters, and two rubber cone ends for non-threaded checks — all organized in a protective blue storage case. It’s designed to fit many modern and older petrol engines so you can diagnose worn rings, leaking valves, or head gasket issues without guesswork.\u003c\/p\u003e\n\n\u003ch3\u003eHow do I use the DAYUAN tester to check cylinder compression?\u003c\/h3\u003e\n\u003cp\u003eStart by removing the spark plug from the cylinder you want to test, then screw in the appropriate adapter or seat a rubber cone for quick checks. Crank the engine several revolutions with the throttle open while watching the gauge; the highest steady reading is the cylinder’s compression. Compare readings across cylinders to identify discrepancies that indicate mechanical problems.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eChoose correct adapter: M10, M12, M14, M18 or 14mm\/18mm spark plug fittings\u003c\/li\u003e\n  \u003cli\u003eUse rubber cones for quick, non-threaded checks\u003c\/li\u003e\n  \u003cli\u003eRecord peak pressure after 4–6 cranks for accuracy\u003c\/li\u003e\n  \u003cli\u003eOpen throttle fully to allow maximum cylinder airflow\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhich engines and plugs will this kit fit?\u003c\/h3\u003e\n\u003cp\u003eThe kit covers a broad range of petrol engines thanks to its threaded fittings and spark plug adapters. It works with standard spark plug ports and many specialized plug types because of the included male-threaded fittings with O-rings and two common spark plug adapters. For unsupported or unusual ports, the rubber cone ends provide a non-invasive alternative to get a quick pressure estimate.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eThreaded fittings: M10, M12, M14, M18 (male with O-ring)\u003c\/li\u003e\n  \u003cli\u003eSpark plug adapters: 14mm and 18mm included\u003c\/li\u003e\n  \u003cli\u003eRubber cone ends for non-threaded or deep plug holes\u003c\/li\u003e\n  \u003cli\u003eSuitable for most petrol automotive and small engine cylinders\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat does the 3\" dual-scale gauge tell me and why it matters?\u003c\/h3\u003e\n\u003cp\u003eThe 3-inch gauge displays pressure in both psi (0–300) and bar (0–20) using an easy-reading dual-color scale, so you can read diagnostics in your preferred unit. A clear, large face reduces parallax error and helps you spot peak and resting pressures quickly. Consistent readings let you compare cylinders and determine the severity of compression loss.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eRange: 0–300 psi and 0–20 bar on a single dial\u003c\/li\u003e\n  \u003cli\u003eLarge 3\" face improves visibility under shop lighting\u003c\/li\u003e\n  \u003cli\u003eDual-color scale simplifies quick interpretation\u003c\/li\u003e\n  \u003cli\u003eUse peak reading after steady revolutions for reliable results\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch3\u003eWhat accessories are included and how do they improve testing?\u003c\/h3\u003e\n\u003cp\u003eThe kit bundles adapters, cones, and fittings so you can test a wide variety of petrol engines without hunting for parts. O-ring sealed male fittings prevent leakage at the connection point, while spark plug adapters let you thread directly into plug holes for accurate readings. The two rubber cone ends enable fast checks when threading is impractical or time is limited.\u003c\/p\u003e\n\u003cul\u003e\n  \u003cli\u003eFour male threaded fittings (M10, M12, M14, M18) with O-rings for tight seals\u003c\/li\u003e\n  \u003cli\u003e14mm and 18mm spark plug adapters for common plug sizes\u003c\/li\u003e\n  \u003cli\u003eTwo rubber cone ends for quick checks without threading\u003c\/li\u003e\n  \u003cli\u003eDurable blue storage case keeps components organized and protected\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cp\u003eWho this is for: the DAYUAN Petrol Engine Compression Tester Kit is ideal for professional mechanics, automotive technicians, and informed DIYers who perform routine engine diagnostics and repairs. If you need a portable, adaptable tool that delivers clear pressure readings across many petrol engines, this kit supplies the fittings and gauge to get repeatable results without extra purchases.\u003c\/p\u003e\n\u003csection class=\"product-faq-snippet\"\u003e\u003ch3\u003eFAQ\u003c\/h3\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Can this kit test both cars and small engines?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. With M10–M18 fittings, 14mm\/18mm adapters, and rubber cones, it fits many automotive and small petrol engines.\u003c\/p\u003e\n\u003c\/div\u003e\n\u003cdiv class=\"faq-item\"\u003e\n\u003cp class=\"faq-q\"\u003eQ: Does the gauge show readings in both psi and bar?\u003c\/p\u003e\n\u003cp class=\"faq-a\"\u003eA: Yes. The 3\" dial displays dual-color scales for 0–300 psi and 0–20 bar for easy conversion.\u003c\/p\u003e\n\u003c\/div\u003e\u003c\/section\u003e","brand":"DAYUAN","offers":[{"title":"Default Title","offer_id":55164512338263,"sku":"B08MVSJJZK","price":31.58,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/1050\/1524\/7191\/files\/dayuan-blue-case-front.jpg?v=1790353012","url":"https:\/\/britishgarage.co.uk\/products\/dayuan-petrol-engine-compression-tester-kit-blue-case-3-dual-scale-gauge-adapters","provider":"British Garage","version":"1.0","type":"link"}