{"product_id":"63mm-180cc-big-bore-kit-for-gy6-125cc-150cc","title":"63mm 180cc Big Bore Kit for GY6 125cc \u0026 150cc","description":"\u003ch2\u003e63mm Big Bore Kit for GY6 125cc and 150cc Engines\u003c\/h2\u003e\u003cp\u003eThis big bore setup raises the displacement of a GY6 engine to 180cc, which adds low-speed pulling power and helps on hills. It suits GY6 125cc and 150cc engines and can be fitted to scooters, recreational vehicles, small cars, and a range of utility machines. If you are browsing \u003ca href=\"\/collections\/gy6-150cc-parts\"\u003eGY6 150cc scooter parts\u003c\/a\u003e, this is one option that can noticeably boost performance. The engine case must be bored out to suit this upgrade before fitting.\u003c\/p\u003e\u003ch3\u003eFull Top-End Set\u003c\/h3\u003e\u003cp\u003eEverything needed for the top end comes in the box: cylinder, piston, circlips, piston ring set, and gaskets. The cylinder has cooling fins to help shed heat, which matters under heavy use. Having all parts in one kit makes the upgrade more straightforward.\u003c\/p\u003e\u003ch3\u003eWhat the Case Needs\u003c\/h3\u003e\u003cp\u003eThe engine case has to be bored to accept the 64.9mm sleeve of the cylinder before anything goes on. Skipping this step can damage the cylinder. You should also think about re-jetting the carburetor or fitting a larger performance carburetor so fuel delivery keeps up. A performance camshaft paired with this kit can add further gains.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eBore:\u003c\/strong\u003e 63mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDisplacement:\u003c\/strong\u003e 180cc (with stock 57.8mm stroke)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSleeve Outer Diameter:\u003c\/strong\u003e 64.9mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCylinder Height:\u003c\/strong\u003e 90.5mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eStud Spacing:\u003c\/strong\u003e 54mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eIncludes:\u003c\/strong\u003e Cylinder, piston, 2 circlips, 5-piece ring set, base gasket, head gasket\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eReplacement Rings:\u003c\/strong\u003e 63mm Piston Ring Set\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOEM Part Number:\u003c\/strong\u003e OPS 164-310\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e GY6 150cc (157QMJ) engine; case boring required on all applications\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eFits:\u003c\/p\u003e\u003cul\u003e\u003cli\u003eGY6 150cc (157QMJ) (54mm stud spacing, case boring required)\u003c\/li\u003e\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eHow to choose:\u003c\/strong\u003e Look up the engine code stamped on the engine case. This kit is listed for the 152QMI, 157QMJ, 161QMK, 1P57QMJ, 1P61QMK, YN1P57QMJ, JJ157QMJ, BN157QMJ and BN161QMK-A codes.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eWhere it goes:\u003c\/strong\u003e Part #1 on the cylinder diagram for the GY6 150cc (157QMJ).\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eOther versions:\u003c\/strong\u003e For the NCY 61mm no-cut kit for 171cc GY6 engines, see \u003ca href=\"\/products\/gy6-61mm-171cc-no-cut-big-bore-kit\"\u003eGY6 61mm 171cc No-Cut Big Bore Kit\u003c\/a\u003e.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eShop more:\u003c\/strong\u003e \u003ca href=\"\/collections\/gy6-150cc-parts\"\u003eGY6 150cc Scooter Parts (157QMJ)\u003c\/a\u003e · \u003ca href=\"\/collections\/gy6-scooter-parts\"\u003eGY6 Scooter Parts\u003c\/a\u003e · \u003ca href=\"\/collections\/scooter-cylinder-kits\"\u003eScooter Big Bore \u0026amp; Cylinder Kits\u003c\/a\u003e · \u003ca href=\"\/collections\/scooter-parts\"\u003eScooter Parts\u003c\/a\u003e\u003c\/p\u003e","brand":"Trend Times Toy Stores","offers":[{"title":"Default Title","offer_id":51138228420665,"sku":"TT-24998","price":123.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0665\/3358\/9049\/files\/rdln-63mm-180cc-big-bore-kit-for-gy6-125cc-150cc-1.jpg?v=1794372925","url":"https:\/\/www.trendtimes.com\/products\/63mm-180cc-big-bore-kit-for-gy6-125cc-150cc","provider":"Trend Times Toy Stores","version":"1.0","type":"link"}