{"product_id":"cvk-main-jet-138-for-scooters-mopeds","title":"Cvk Main Jet (# 138) for Scooters \u0026 Mopeds","description":"\u003ch2\u003eCvk Main Jet (#138) for 139QMB and GY6 Scooters\u003c\/h2\u003e\u003cp\u003eThe Cvk Main Jet (#138) is an accurately made part built for scooters and mopeds that use 139QMB and GY6 engines. Fitting a new one helps the fuel flow correctly and can make the engine run better. It belongs to the \u003ca href=\"\/collections\/scooter-carburetors\"\u003escooter carburetors \u0026amp; jets\u003c\/a\u003e range and has a key job in how the bike runs. It works with a range of CVK carburetors that take a 5mm main jet.\u003c\/p\u003e\u003ch3\u003eJet Specifications\u003c\/h3\u003e\u003cp\u003eThis main jet uses a Keihin round design, which is a dependable choice for performance setups. It has an M5x0.80 thread and measures 8mm overall in length, so it sits properly in the carburetor slot. Getting the jetting dialed in may take some testing before you find what works best for your particular setup.\u003c\/p\u003e\u003ch3\u003eWhen to Replace Your Main Jet\u003c\/h3\u003e\u003cp\u003eConsider swapping the main jet if the throttle feels slow to respond, the idle is uneven, or you have changed something on the engine that could alter fuel flow. Keeping up with routine maintenance and correct jetting helps your scooter stay smooth and efficient.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eType:\u003c\/strong\u003e Main Jet\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eThread Size:\u003c\/strong\u003e M5x0.80\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOverall Length:\u003c\/strong\u003e 8mm\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e 139QMB\/GY6 50cc and 80cc engines and 157QMJ\/QMK\/QMI 125cc, 150cc\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003eFits:\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e139QMB-based 50cc and 80cc engines (engine codes 139QMA, 139QMB, 1P39QMB, 1P39QMA-2, YN139QMB, JJ1P39QMB, 139FMA-2, BD1P39QMB, BN139QMB, 147QMD, other QMA and QMB models)\u003c\/li\u003e\n\u003cli\u003e157QMJ-based 125cc, 150cc and 169cc engines (engine codes 157QMJ, 161QMK, 152QMI, 1P61QMK, YN1P57QMJ, 1P52FMI, 154FMI, JJ157QMJ, 1P57QMJ, BN157QMJ, BN161QMK-A, other QMJ, QMK and QMI models)\u003c\/li\u003e\n\u003cli\u003eAny engine with a code containing QM or FM and a 5mm main jet slot CVK carburetor\u003c\/li\u003e\n\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eHow to choose:\u003c\/strong\u003e Make sure the 5mm main jet slot on your CVK carburetor and the M5x0.80 thread both match; this jet is 8mm overall length.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eShop more:\u003c\/strong\u003e \u003ca href=\"\/collections\/scooter-carburetors\"\u003eBrowse Scooter Carburetors \u0026amp; Jets\u003c\/a\u003e · \u003ca href=\"\/collections\/scooter-parts\"\u003eBrowse Scooter Parts\u003c\/a\u003e\u003c\/p\u003e","brand":"Trend Times Toy Stores","offers":[{"title":"Default Title","offer_id":51138616361017,"sku":"TT-26426","price":3.58,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0665\/3358\/9049\/files\/cvk-main-jet-138-1.jpg?v=1794376403","url":"https:\/\/www.trendtimes.com\/products\/cvk-main-jet-138-for-scooters-mopeds","provider":"Trend Times Toy Stores","version":"1.0","type":"link"}