{"product_id":"gy6-50cc-80cc-crankshaft","title":"GY6 50cc Crankshaft for 50cc \u0026 80cc Scooter Engines – 16 or 22 Teeth, 45# Steel","description":"\u003ch2\u003eGY6 50cc Crankshaft for 50cc and 80cc Scooter Engines\u003c\/h2\u003e\n\u003cp\u003eThis GY6 50cc crankshaft is a replacement crankshaft and connecting rod assembly for GY6-type 50cc and 80cc scooter engines. It is made from 45# medium carbon steel and comes in two versions, with a 16-tooth or a 22-tooth oil pump drive gear, so you can match the gear on your original crankshaft. Easy Life Markets sells it for scooter owners and repair shops rebuilding the bottom end of these small four-stroke engines.\u003c\/p\u003e\n\n\u003cp\u003eThe GY6 design is one of the most widely used small scooter engines, found in many brands of 50cc scooters and mopeds. The 50cc version (often called 139QMB) and the 80cc big bore version share the same basic crankcase, which is why a single crankshaft is listed for both. A worn crankshaft or connecting rod bearing is a common reason for noise and vibration on older, high-mileage scooters.\u003c\/p\u003e\n\n\u003ch2\u003eChoose Your Version: 16 Teeth or 22 Teeth\u003c\/h2\u003e\n\u003cp\u003eThe oil pump on GY6 50cc engines is driven from the crankshaft, and two different drive gear sizes were used: 16 teeth and 22 teeth. The two versions are not interchangeable, because the gear must match the rest of your oil pump drive.\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003e16 Teeth:\u003c\/strong\u003e choose this if your original crankshaft has a 16-tooth oil pump gear.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e22 Teeth:\u003c\/strong\u003e choose this if your original crankshaft has a 22-tooth oil pump gear.\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eCount the teeth on your old crankshaft's gear before ordering. The product photos include a picture that shows the gear versions.\u003c\/p\u003e\n\n\u003ch2\u003eWhat Is Included\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e1 x crankshaft with connecting rod, in the gear version you select\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eMain bearings, oil seals, cam chain and gaskets are not listed as included.\u003c\/p\u003e\n\n\u003ch2\u003eSpecifications\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eProduct type:\u003c\/strong\u003e Scooter engine crankshaft and connecting rod assembly\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eListed engines:\u003c\/strong\u003e GY6 50cc and 80cc\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eMaterial:\u003c\/strong\u003e 45# medium carbon steel\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eVersions:\u003c\/strong\u003e 16-tooth or 22-tooth oil pump gear\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQuantity:\u003c\/strong\u003e 1 crankshaft\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSKU:\u003c\/strong\u003e CJYD232049301AZ (16 teeth), CJYD232049302BY (22 teeth)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eThe material grade is a common engineering steel. You can read more about \u003ca href=\"https:\/\/en.wikipedia.org\/wiki\/Carbon_steel\" target=\"_blank\" rel=\"noopener\"\u003ecarbon steel\u003c\/a\u003e and why medium carbon grades are used for shafts and gears.\u003c\/p\u003e\n\n\u003ch2\u003eChecking Fitment\u003c\/h2\u003e\n\u003cp\u003eNot every 50cc scooter uses a GY6 engine. Many use a two-stroke engine or a different four-stroke design. Before ordering:\u003c\/p\u003e\n\u003col\u003e\n\u003cli\u003e\n\u003cstrong\u003eConfirm your engine is a GY6 50cc or 80cc\u003c\/strong\u003e four-stroke, usually marked 139QMB or similar on the crankcase.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCount the oil pump gear teeth\u003c\/strong\u003e on your old crankshaft (16 or 22).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCompare the crankshaft\u003c\/strong\u003e with our photos: shaft lengths on both sides, splines, threads and the cam chain sprocket.\u003c\/li\u003e\n\u003c\/ol\u003e\n\u003cp\u003eIf anything looks different, \u003ca href=\"\/pages\/contact\"\u003esend us photos of your old crankshaft\u003c\/a\u003e before ordering.\u003c\/p\u003e\n\n\u003ch2\u003eSigns Your Crankshaft Needs Replacing\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eKnocking or rattling from the bottom end\u003c\/li\u003e\n\u003cli\u003eStrong vibration that gets worse with speed\u003c\/li\u003e\n\u003cli\u003ePlay in the connecting rod big end when checked by hand\u003c\/li\u003e\n\u003cli\u003eDamaged splines, keyway or threads on the variator or magneto side\u003c\/li\u003e\n\u003cli\u003eOil seal leaks that keep coming back because the shaft runs out of true\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eRebuild Tips\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003eReplacing the crankshaft means splitting the crankcase, so plan it as a full bottom-end rebuild.\u003c\/li\u003e\n\u003cli\u003eFit new main bearings and crankshaft oil seals at the same time.\u003c\/li\u003e\n\u003cli\u003eCheck the cam chain and tensioner, and the oil pump and its drive, while the engine is open.\u003c\/li\u003e\n\u003cli\u003eClean the crankcase halves thoroughly and use a new crankcase gasket.\u003c\/li\u003e\n\u003cli\u003eLine up the timing marks on the cam sprocket and crankshaft when reassembling the top end.\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003ch2\u003eAfter the Rebuild\u003c\/h2\u003e\n\u003cp\u003eRun the engine gently for the first few hundred kilometers, change the oil early to flush out assembly debris, and then keep to regular oil changes. Small scooter engines hold very little oil, so checking the level often helps protect the new crankshaft.\u003c\/p\u003e\n\n\u003ch2\u003eHow the GY6 50cc Bottom End Works\u003c\/h2\u003e\n\u003cp\u003eIn a GY6 50cc engine, the crankshaft sits in two main bearings in the crankcase. One end carries the magneto rotor and the cam chain sprocket, and the other end drives the variator of the automatic CVT transmission. The oil pump is driven by a gear on the crankshaft, which is why the tooth count matters. Because the variator end carries so much load, a worn crankshaft often shows up first as a noisy or wobbling variator, or as a leaking oil seal on that side.\u003c\/p\u003e\n\u003cp\u003eWhen you strip the engine, check the crankshaft runout, the big-end play and the condition of the variator splines. If any of these are out of limits, fitting a new crankshaft assembly is the most reliable repair and saves you from rebuilding the engine twice.\u003c\/p\u003e\n\n\u003ch2\u003eWho This Crankshaft Is For\u003c\/h2\u003e\n\u003cp\u003eThis crankshaft suits scooter repair shops, riders who maintain their own GY6 50cc or 80cc scooter, and anyone reviving a noisy or seized small four-stroke engine.\u003c\/p\u003e\n\n\u003ch2\u003eCommon Questions\u003c\/h2\u003e\n\u003cp\u003e\u003cstrong\u003eWill it fit a GY6 125cc or 150cc engine?\u003c\/strong\u003e No. The 125cc and 150cc GY6 engines use a different, larger crankshaft.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eWhich gear version do I need?\u003c\/strong\u003e Count the teeth on the oil pump gear of your old crankshaft, and choose 16 or 22 teeth to match.\u003c\/p\u003e\n\n\u003ch2\u003eBuy the GY6 50cc Crankshaft at Easy Life Markets\u003c\/h2\u003e\n\u003cp\u003eYou can order this crankshaft right here. Select the 16-tooth or 22-tooth version above. The current price and availability are shown on this page. Please read our \u003ca href=\"\/pages\/return-refund-policy\"\u003ereturn and refund policy\u003c\/a\u003e before buying.\u003c\/p\u003e\n\n\u003ch2\u003eRelated Products\u003c\/h2\u003e\n\u003cul\u003e\n\u003cli\u003e\u003ca href=\"\/products\/gy6-125cc-piston-kit\"\u003eGY6 125cc piston kit\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/57-4mm-scooter-piston-kit\"\u003e57.4mm scooter piston kit\u003c\/a\u003e\u003c\/li\u003e\n\u003cli\u003e\u003ca href=\"\/products\/off-road-motorcycle-crankshaft-assembly\"\u003eoff-road motorcycle crankshaft assembly\u003c\/a\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eBrowse our \u003ca href=\"\/collections\/crankshafts\"\u003ecrankshafts collection\u003c\/a\u003e and \u003ca href=\"\/collections\/engine-parts\"\u003eengine parts\u003c\/a\u003e.\u003c\/p\u003e\n\n\u003ch2\u003eProduct Photos\u003c\/h2\u003e\n\u003cp\u003e\n\u003cimg src=\"https:\/\/oss-cf.cjdropshipping.com\/product\/2025\/03\/10\/07\/c83785ec-a5cb-4b6e-a7c1-99b3e8c11b24.jpg\" alt=\"GY6 50cc crankshaft\" style=\"max-width:100%;\"\u003e\n\u003cimg src=\"https:\/\/oss-cf.cjdropshipping.com\/product\/2025\/03\/10\/07\/3e20ccf9-d8ac-4f1c-8bd0-8292c3794367.jpg\" alt=\"GY6 50cc crankshaft detail\" style=\"max-width:100%;\"\u003e\n\u003cimg src=\"https:\/\/oss-cf.cjdropshipping.com\/product\/2025\/03\/10\/07\/ae6e8db3-173c-421f-8499-df12ce237742.jpg\" alt=\"GY6 50cc crankshaft detail\" style=\"max-width:100%;\"\u003e\n\u003cimg src=\"https:\/\/oss-cf.cjdropshipping.com\/product\/2025\/03\/09\/10\/e6989abf-2b92-4f28-98c9-2942cc71e9b4_trans.jpeg\" alt=\"GY6 50cc crankshaft 16 and 22 teeth versions\" style=\"max-width:100%;\"\u003e\n\u003cimg src=\"https:\/\/oss-cf.cjdropshipping.com\/product\/2025\/03\/09\/10\/d750126c-6e85-4b02-a764-ba16439ef19f_trans.jpeg\" alt=\"GY6 50cc crankshaft detail\" style=\"max-width:100%;\"\u003e\n\u003cimg src=\"https:\/\/oss-cf.cjdropshipping.com\/product\/2025\/03\/09\/10\/ebd83c52-378d-4506-8456-c8ca92fbb81e_trans.jpeg\" alt=\"GY6 50cc crankshaft detail\" style=\"max-width:100%;\"\u003e\n\u003cimg src=\"https:\/\/oss-cf.cjdropshipping.com\/product\/2025\/03\/10\/07\/22dccbfa-dac2-4de4-b265-924b224135a0.jpg\" alt=\"GY6 50cc crankshaft detail\" style=\"max-width:100%;\"\u003e\n\u003c\/p\u003e","brand":"easylife markets","offers":[{"title":"16 Teeth","offer_id":46969698123937,"sku":"CJYD232049301AZ","price":279.31,"currency_code":"AED","in_stock":true},{"title":"22 Teeth","offer_id":46969698156705,"sku":"CJYD232049302BY","price":279.31,"currency_code":"AED","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0751\/2086\/9537\/files\/35b69797-766f-443f-85a5-bade546b25e7_trans.jpg?v=1788567524","url":"https:\/\/easylifemarketplace.com\/products\/gy6-50cc-80cc-crankshaft","provider":"Easy Life Markets","version":"1.0","type":"link"}