{"product_id":"ums-7-cylinder-160cc-petrol-radial-engine-4-stroke-scale-aircraft-powerplant","title":"UMS 7-Cylinder 90cc Petrol Radial Engine – 4-Stroke Scale Aircraft Powerplant","description":"\u003cp data-start=\"3602\" data-end=\"3750\"\u003e\u003cspan style=\"font-size: 0.875rem;\"\u003eThe \u003c\/span\u003e\u003cstrong data-start=\"306\" data-end=\"350\" style=\"font-size: 0.875rem;\"\u003eUMS 7-Cylinder 90cc Petrol Radial Engine\u003c\/strong\u003e\u003cspan style=\"font-size: 0.875rem;\"\u003e delivers authentic seven-cylinder radial realism in a compact and lightweight 4-stroke package. Designed for smaller scale aircraft and warbirds, it combines smooth power delivery, CNC precision engineering, and long-term durability.\u003c\/span\u003e\u003c\/p\u003e\n\u003ch2 data-start=\"591\" data-end=\"617\"\u003e\u003cstrong data-start=\"594\" data-end=\"617\"\u003eProduct Description\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp data-start=\"619\" data-end=\"1010\"\u003eThe \u003cstrong data-start=\"623\" data-end=\"651\"\u003eUMS 7-90cc Radial Engine\u003c\/strong\u003e is a compact, high-quality 4-stroke petrol engine built for scale aircraft enthusiasts who demand authentic appearance and dependable performance. Its classic \u003cstrong data-start=\"811\" data-end=\"846\"\u003e7-cylinder radial configuration\u003c\/strong\u003e provides the unmistakable look and sound of full-size aviation engines, making it ideal for detailed warbirds, vintage aircraft, and museum-quality scale projects.\u003c\/p\u003e\n\u003cp data-start=\"1012\" data-end=\"1198\"\u003eWith a \u003cstrong data-start=\"1019\" data-end=\"1040\"\u003e90cc displacement\u003c\/strong\u003e, this engine offers strong, balanced power for smaller and mid-size scale aircraft while maintaining a lightweight design for optimal flight characteristics.\u003c\/p\u003e\n\u003cp data-start=\"1200\" data-end=\"1247\"\u003eSupplied \u003cstrong data-start=\"1209\" data-end=\"1225\"\u003eready to run\u003c\/strong\u003e, the engine includes:\u003c\/p\u003e\n\u003cul data-start=\"1249\" data-end=\"1347\"\u003e\n\u003cli data-start=\"1249\" data-end=\"1275\"\u003e\n\u003cp data-start=\"1251\" data-end=\"1275\"\u003eExhaust collector ring\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1276\" data-end=\"1306\"\u003e\n\u003cp data-start=\"1278\" data-end=\"1306\"\u003eElectronic ignition system\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1307\" data-end=\"1322\"\u003e\n\u003cp data-start=\"1309\" data-end=\"1322\"\u003eSpark plugs\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1323\" data-end=\"1347\"\u003e\n\u003cp data-start=\"1325\" data-end=\"1347\"\u003eDurable engine mount\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"1349\" data-end=\"1535\"\u003eIntegrated \u003cstrong data-start=\"1360\" data-end=\"1393\"\u003echoke and throttle bellcranks\u003c\/strong\u003e simplify installation and ensure smooth throttle response, making setup straightforward for both experienced builders and advanced hobbyists.\u003c\/p\u003e\n\u003cp data-start=\"1537\" data-end=\"1842\"\u003eManufactured using \u003cstrong data-start=\"1556\" data-end=\"1607\"\u003eCNC-machined aluminium and bar stock components\u003c\/strong\u003e, the engine delivers precision tolerances and consistent performance. The \u003cstrong data-start=\"1682\" data-end=\"1736\"\u003eaircraft-grade alloy cylinder heads and crankcases\u003c\/strong\u003e provide excellent strength-to-weight balance, helping maintain correct centre of gravity in scale builds.\u003c\/p\u003e\n\u003cp data-start=\"1844\" data-end=\"1890\"\u003eInternally, durability is prioritised through:\u003c\/p\u003e\n\u003cul data-start=\"1892\" data-end=\"2132\"\u003e\n\u003cli data-start=\"1892\" data-end=\"1962\"\u003e\n\u003cp data-start=\"1894\" data-end=\"1962\"\u003eHeavy-duty double-bearing crankshaft for stable high-RPM operation\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"1963\" data-end=\"2017\"\u003e\n\u003cp data-start=\"1965\" data-end=\"2017\"\u003eBillet aluminium pistons with hardened steel rings\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2018\" data-end=\"2077\"\u003e\n\u003cp data-start=\"2020\" data-end=\"2077\"\u003eHard-chromed and lapped cylinder bores for reduced wear\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2078\" data-end=\"2132\"\u003e\n\u003cp data-start=\"2080\" data-end=\"2132\"\u003eHardened steel camshafts for reliable valve timing\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"2134\" data-end=\"2306\"\u003eDesigned to run on \u003cstrong data-start=\"2153\" data-end=\"2177\"\u003e87–110 octane petrol\u003c\/strong\u003e with a \u003cstrong data-start=\"2185\" data-end=\"2213\"\u003e32:1 fuel-to-oil mixture\u003c\/strong\u003e, the UMS 7-90cc offers reliable starting, smooth throttle transition, and long service life.\u003c\/p\u003e\n\u003cp data-start=\"2308\" data-end=\"2467\"\u003eWhether powering a scale warbird or a detailed classic aircraft, this engine delivers the perfect balance of \u003cstrong data-start=\"2417\" data-end=\"2466\"\u003erealism, performance, and engineering quality\u003c\/strong\u003e.\u003c\/p\u003e\n\u003ch2 data-start=\"2474\" data-end=\"2493\"\u003e\u003cstrong data-start=\"2477\" data-end=\"2493\"\u003eKey Features\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cul data-start=\"2495\" data-end=\"2987\"\u003e\n\u003cli data-start=\"2495\" data-end=\"2539\"\u003e\n\u003cp data-start=\"2497\" data-end=\"2539\"\u003e7-cylinder 4-stroke petrol radial engine\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2540\" data-end=\"2596\"\u003e\n\u003cp data-start=\"2542\" data-end=\"2596\"\u003e90cc displacement – ideal for smaller scale aircraft\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2597\" data-end=\"2638\"\u003e\n\u003cp data-start=\"2599\" data-end=\"2638\"\u003eAuthentic radial sound and appearance\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2639\" data-end=\"2696\"\u003e\n\u003cp data-start=\"2641\" data-end=\"2696\"\u003eReady-to-run package with ignition and collector ring\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2697\" data-end=\"2750\"\u003e\n\u003cp data-start=\"2699\" data-end=\"2750\"\u003eCNC-machined aluminium and bar stock construction\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2751\" data-end=\"2805\"\u003e\n\u003cp data-start=\"2753\" data-end=\"2805\"\u003eAircraft-grade alloy cylinder heads and crankcases\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2806\" data-end=\"2850\"\u003e\n\u003cp data-start=\"2808\" data-end=\"2850\"\u003eDouble-bearing crankshaft for durability\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2851\" data-end=\"2895\"\u003e\n\u003cp data-start=\"2853\" data-end=\"2895\"\u003eBillet pistons with hardened steel rings\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2896\" data-end=\"2935\"\u003e\n\u003cp data-start=\"2898\" data-end=\"2935\"\u003eHard-chromed, lapped cylinder bores\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"2936\" data-end=\"2987\"\u003e\n\u003cp data-start=\"2938\" data-end=\"2987\"\u003eCompatible with 87–110 octane petrol (32:1 mix)\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 data-start=\"2994\" data-end=\"3012\"\u003e\u003cstrong data-start=\"2997\" data-end=\"3012\"\u003ePerfect For\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cul data-start=\"3014\" data-end=\"3214\"\u003e\n\u003cli data-start=\"3014\" data-end=\"3043\"\u003e\n\u003cp data-start=\"3016\" data-end=\"3043\"\u003eSmaller scale RC warbirds\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3044\" data-end=\"3088\"\u003e\n\u003cp data-start=\"3046\" data-end=\"3088\"\u003eVintage and golden-era aircraft replicas\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3089\" data-end=\"3136\"\u003e\n\u003cp data-start=\"3091\" data-end=\"3136\"\u003eBuilders seeking compact 7-cylinder realism\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3137\" data-end=\"3165\"\u003e\n\u003cp data-start=\"3139\" data-end=\"3165\"\u003eScale competition models\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3166\" data-end=\"3214\"\u003e\n\u003cp data-start=\"3168\" data-end=\"3214\"\u003eAdvanced hobbyists and professional builders\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003ch2 data-start=\"3221\" data-end=\"3242\"\u003e\u003cstrong data-start=\"3224\" data-end=\"3242\"\u003eSpecifications\u003c\/strong\u003e\u003c\/h2\u003e\n\u003cp data-start=\"3244\" data-end=\"3580\"\u003e\u003cstrong data-start=\"3244\" data-end=\"3260\"\u003eEngine Type:\u003c\/strong\u003e 4-Stroke\u003cbr data-start=\"3269\" data-end=\"3272\"\u003e\u003cstrong data-start=\"3272\" data-end=\"3286\"\u003eCylinders:\u003c\/strong\u003e 7 (ABC Type)\u003cbr data-start=\"3299\" data-end=\"3302\"\u003e\u003cstrong data-start=\"3302\" data-end=\"3319\"\u003eDisplacement:\u003c\/strong\u003e 90cc\u003cbr data-start=\"3324\" data-end=\"3327\"\u003e\u003cstrong data-start=\"3327\" data-end=\"3336\"\u003eBore:\u003c\/strong\u003e 25.1mm\u003cbr data-start=\"3343\" data-end=\"3346\"\u003e\u003cstrong data-start=\"3346\" data-end=\"3357\"\u003eStroke:\u003c\/strong\u003e 26.0mm\u003cbr data-start=\"3364\" data-end=\"3367\"\u003e\u003cstrong data-start=\"3367\" data-end=\"3386\"\u003eApprox. Thrust:\u003c\/strong\u003e 9.5kgf @ 24×10 prop\u003cbr data-start=\"3406\" data-end=\"3409\"\u003e\u003cstrong data-start=\"3409\" data-end=\"3423\"\u003eRPM Range:\u003c\/strong\u003e 1,000 – 5,500\u003cbr data-start=\"3437\" data-end=\"3440\"\u003e\u003cstrong data-start=\"3440\" data-end=\"3478\"\u003eWeight (with silencer \u0026amp; ignition):\u003c\/strong\u003e Approx. 3.5kg\u003cbr data-start=\"3492\" data-end=\"3495\"\u003e\u003cstrong data-start=\"3495\" data-end=\"3515\"\u003eEngine Diameter:\u003c\/strong\u003e 230mm\u003cbr data-start=\"3521\" data-end=\"3524\"\u003e\u003cstrong data-start=\"3524\" data-end=\"3542\"\u003eEngine Length:\u003c\/strong\u003e 170mm\u003cbr data-start=\"3548\" data-end=\"3551\"\u003e\u003cstrong data-start=\"3551\" data-end=\"3578\"\u003eRecommended Propellers:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul data-start=\"3581\" data-end=\"3752\"\u003e\n\u003cli data-start=\"3581\" data-end=\"3598\"\u003e\n\u003cp data-start=\"3583\" data-end=\"3598\"\u003e2-Blade 26×10\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli data-start=\"3599\" data-end=\"3752\"\u003e\n\u003cp data-start=\"3601\" data-end=\"3752\"\u003e2-Blade 24×12\u003cbr data-start=\"3614\" data-end=\"3617\"\u003e\u003cstrong data-start=\"3617\" data-end=\"3634\"\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-start=\"3601\" data-end=\"3752\"\u003e\u003cstrong data-start=\"3617\" data-end=\"3634\"\u003eMuffler Type:\u003c\/strong\u003e Collector Ring\u003cbr data-start=\"3649\" data-end=\"3652\"\u003e\u003cstrong data-start=\"3652\" data-end=\"3667\"\u003eSpark Plug:\u003c\/strong\u003e 1\/4-32\u003cbr data-start=\"3674\" data-end=\"3677\"\u003e\u003cstrong data-start=\"3677\" data-end=\"3693\"\u003eCarburettor:\u003c\/strong\u003e Walbro\u003cbr data-start=\"3700\" data-end=\"3703\"\u003e\u003cstrong data-start=\"3703\" data-end=\"3717\"\u003eFuel Type:\u003c\/strong\u003e Petrol (87–110 octane, 32:1 mix)\u003c\/p\u003e\n\u003ch3 data-end=\"3529\" data-start=\"3491\"\u003e\u003cstrong data-end=\"3529\" data-start=\"3495\"\u003eWhy Buy from Probuild Aircraft\u003c\/strong\u003e\u003c\/h3\u003e\n\u003cp data-end=\"3723\" data-start=\"3530\"\u003e✅ Official UK stockist – 100% genuine UMS engines\u003cbr data-end=\"3582\" data-start=\"3579\"\u003e✅ Trusted by top international pilots and builders\u003cbr data-end=\"3635\" data-start=\"3632\"\u003e✅ Fast UK shipping and secure packaging\u003cbr data-end=\"3677\" data-start=\"3674\"\u003e✅ Supplying and supporting pilots since 1993\u003c\/p\u003e\n\u003cp data-end=\"3723\" data-start=\"3530\"\u003eManual:\u003c\/p\u003e\n\u003cp data-end=\"3723\" data-start=\"3530\"\u003e\u003ca rel=\"noopener\" href=\"https:\/\/ch-ignitions.com\/wp-content\/uploads\/2020\/03\/ums-gas-radial-engine-manual-9-115.pdf\" target=\"_blank\"\u003e\u003cimg height=\"351\" width=\"233\" alt=\"\" src=\"https:\/\/cdn.shopify.com\/s\/files\/1\/0934\/7711\/0146\/files\/Screenshot_2026-02-04_115553.png?v=1770206937\"\u003e\u003c\/a\u003e\u003c\/p\u003e","brand":"UMS Engines","offers":[{"title":"Default Title","offer_id":56341649719682,"sku":"UMS7-90","price":1950.0,"currency_code":"GBP","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0934\/7711\/0146\/files\/Gas-Radial-7-90cc.jpg?v=1770811672","url":"https:\/\/www.probuild-uk.co.uk\/products\/ums-7-cylinder-160cc-petrol-radial-engine-4-stroke-scale-aircraft-powerplant","provider":"Probuild Aircraft Ltd","version":"1.0","type":"link"}