{"product_id":"polini-thor-303","title":"Polini THOR 303","description":"\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eThe \u003cstrong\u003eThor 303\u003c\/strong\u003e is the highest displacement engine in the Polini Thor series. Its cylinder, crankshaft, carburetor, airbox, CDI, and exhaust system have all been completely redesigned to improve performance and in-flight safety.\u003c\/p\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eDelivering \u003cstrong\u003e38 HP at 8000 RPM\u003c\/strong\u003e, the Thor 303 can generate up to \u003cstrong\u003e265 lbs of static thrust\u003c\/strong\u003e with a \u003cstrong\u003e63-inch\u003c\/strong\u003e propeller.\u003c\/p\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eAt a cruising RPM of \u003cstrong\u003e4500\u003c\/strong\u003e, it consumes just \u003cstrong\u003e0.8 gallons per hour\u003c\/strong\u003e, producing approximately \u003cstrong\u003e66 lbs of thrust\u003c\/strong\u003e in level flight.\u003c\/p\u003e\u003ch3 style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eAvailable Versions\u003c\/h3\u003e\u003cul data-rte-list=\"true\"\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003eThor 303 with Manual Flash Starter\u003c\/strong\u003e\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003eThor 303 with Electric + Manual Flash Starter\u003c\/strong\u003e\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003eThor 303 Dual Spark (Dual Ignition)\u003c\/strong\u003e\u003c\/p\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eThe \u003cstrong\u003eDual Spark version\u003c\/strong\u003e meets top-tier aviation safety standards and comes with electric and manual starters, dual CDI units, and fully independent redundant ignitions.\u003c\/p\u003e\u003ch3 style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e🛡️ Flight Safety \u0026amp; Testing\u003c\/h3\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eThe Thor 303 is the product of \u003cstrong\u003e3 years of development\u003c\/strong\u003e, including dyno bench testing and real-world flights by Polini’s team of professional pilots. Every engine is \u003cstrong\u003etested and inspected individually\u003c\/strong\u003e before delivery.\u003c\/p\u003e\u003ch3 style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e🧱 Cylinder Specs\u003c\/h3\u003e\u003cul data-rte-list=\"true\"\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003eDisplacement:\u003c\/strong\u003e 281 cc\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003eBore × Stroke:\u003c\/strong\u003e 2.99 × 2.44 inches (76 × 62 mm)\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003eStatic Thrust:\u003c\/strong\u003e 265 lbs with a 63-inch prop\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003eDesign:\u003c\/strong\u003e 5 transfer ports for high and balanced output across all RPM\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003eHead:\u003c\/strong\u003e Optimized combustion chamber for faster flame front\u003c\/p\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3 style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e🔇 Exhaust \/ Muffler\u003c\/h3\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003ePolini developed a \u003cstrong\u003elightweight, low-noise\u003c\/strong\u003e exhaust specifically for the Thor 303. Its compact expansion chamber improves performance across all RPM ranges. Mounted with a spherical joint, the muffler allows free movement and reduces vibration—extending durability.\u003c\/p\u003e\u003ch3 style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e🧃 Carburetor (Dell’Orto VHST 28mm)\u003c\/h3\u003e\u003cul data-rte-list=\"true\"\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eResistant to changes in altitude, humidity, and pressure\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eStable fuel delivery across different climates\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eIncludes a manual drain valve to empty fuel and prevent leakage\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eOptional Polini starter control for safe engine start\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eAllows precise tuning for smooth, powerful output\u003c\/p\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3 style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e🌬️ Air Box \u0026amp; Filter\u003c\/h3\u003e\u003cul data-rte-list=\"true\"\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eFluid-dynamically optimized to stabilize airflow\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eFeatures an S-curve design to reduce turbulence\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eUses polyurethane foam with 30 PPI (pores per inch)\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eSplit-design allows easy access and replacement during service\u003c\/p\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3 style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e❄️ Cooling System\u003c\/h3\u003e\u003cul data-rte-list=\"true\"\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003eCompact Radiator Size:\u003c\/strong\u003e 14 × 7.9 inches (355 × 200 mm)\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e18-core high-efficiency radiator with expansion tank\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003ePressure cap rated to \u003cstrong\u003e20 psi (1.4 bar)\u003c\/strong\u003e\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eDriven by a \u003cstrong\u003e1.18-inch (30 mm)\u003c\/strong\u003e mechanical water pump\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eBlue silicone hoses with Polini branding\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eThermostat prevents temps from dropping below 140°F (60°C)\u003c\/p\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3 style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e💨 Reed Valve System\u003c\/h3\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003ePolini's custom reed valve setup includes \u003cstrong\u003e6 carbon-fiber petals\u003c\/strong\u003e, engineered for precise and responsive airflow throughout the full RPM range. The intake leads directly to the crankcase for optimized performance.\u003c\/p\u003e\u003ch3 style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e🧩 Engine Crankcase\u003c\/h3\u003e\u003cul data-rte-list=\"true\"\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eCast aluminum with high-silicon content\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eCNC-machined for perfect tolerances\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eReinforced in high-stress areas\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eTBO (Time Between Overhaul): \u003cstrong\u003eup to 400 hours\u003c\/strong\u003e\u003c\/p\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3 style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e⚙️ Crankshaft\u003c\/h3\u003e\u003cul data-rte-list=\"true\"\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eConstructed from high-grade steel\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003ePrecision-balanced to eliminate vibrations\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eFitted with high-performance bearings\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eCNC-controlled production ensures perfect centering\u003c\/p\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3 style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e🔁 Gearbox, Countershaft, and Clutch\u003c\/h3\u003e\u003cul data-rte-list=\"true\"\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eIntegrated \u003cstrong\u003ecentrifugal clutch\u003c\/strong\u003e (prop stays idle at low RPM for safety)\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\n\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eTwo reduction ratios available:\u003c\/p\u003e\n\u003cul data-rte-list=\"true\"\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003e2.8:1\u003c\/strong\u003e for \u003cstrong\u003e55-inch (140 cm)\u003c\/strong\u003e propellers\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003e3.2:1\u003c\/strong\u003e for larger props\u003c\/p\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003eHelical gear\u003c\/strong\u003e design reverses prop rotation and softens torque\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003eBalancing countershaft\u003c\/strong\u003e reduces piston-induced vibrations for smoother flight\u003c\/p\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3 style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e⚡ Electronic Ignition\u003c\/h3\u003e\u003cul data-rte-list=\"true\"\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eCustom CDI system with auto-advancing timing based on RPM\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eSmooth throttle response and easy starts\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003eDual Spark Version:\u003c\/strong\u003e Includes 2 CDIs, 2 stators, 2 coils, and 2 spark plugs for maximum redundancy and reliability\u003c\/p\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3 style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e🔄 Flash Starter\u003c\/h3\u003e\u003cul data-rte-list=\"true\"\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eManual pull-start system with ergonomic handle\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eReinforced internals for extended life\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eAvailable on all versions (including those with electric start)\u003c\/p\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3 style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e🔌 Fixing System\u003c\/h3\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eAll Thor engines, including the 303, use the \u003cstrong\u003esame mounting points\u003c\/strong\u003e. This simplifies frame design and allows easy upgrades across the entire Thor lineup. Engines come \u003cstrong\u003efully assembled with all mounting hardware\u003c\/strong\u003e and, for electric versions, plug-and-play wiring and battery.\u003c\/p\u003e\u003ch3 style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e🛩 Recommended Use\u003c\/h3\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eDue to its power, the Thor 303 is ideal for:\u003c\/p\u003e\u003cul data-rte-list=\"true\"\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003eSingle or tandem trikes\u003c\/strong\u003e\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003eDelta trikes\u003c\/strong\u003e\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003eThree-axis ultralights\u003c\/strong\u003e\u003c\/p\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003e\u003cstrong\u003eUAVs (Unmanned Aerial Vehicles)\u003c\/strong\u003e\u003c\/p\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp style=\"white-space:pre-wrap;\" data-rte-preserve-empty=\"true\"\u003eFor \u003cstrong\u003esingle-seat paramotors\u003c\/strong\u003e, this engine is \u003cstrong\u003erecommended for experienced pilots\u003c\/strong\u003e and \u003cstrong\u003ecompetition use only\u003c\/strong\u003e (e.g. slalom racing).\u003c\/p\u003e","brand":"Polini Motari","offers":[{"title":"Pull Start \/ 2.8:1","offer_id":50108880519391,"sku":"928.000.100","price":4149.99,"currency_code":"USD","in_stock":true},{"title":"Pull Start \/ 3.2:1","offer_id":50108880552159,"sku":"928.000.101","price":4149.99,"currency_code":"USD","in_stock":true},{"title":"Electric Starter \/ 2.8:1","offer_id":50108880584927,"sku":"928.000.110","price":4699.99,"currency_code":"USD","in_stock":true},{"title":"Electric Starter \/ 3.2:1","offer_id":50108880617695,"sku":"928.000.111","price":4699.99,"currency_code":"USD","in_stock":true},{"title":"Dual Ignition and Electric Start \/ 2.8:1","offer_id":50108880650463,"sku":"928.000.120","price":5379.99,"currency_code":"USD","in_stock":true},{"title":"Dual Ignition and Electric Start \/ 3.2:1","offer_id":50108880683231,"sku":"928.000.121","price":5379.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0805\/1045\/1935\/files\/THOR_303_maxi.webp?v=1781238609","url":"https:\/\/www.flyminimax.com\/products\/polini-thor-303","provider":"Mini-Max USA","version":"1.0","type":"link"}