{"product_id":"main-jet-103-for-si-carbs-for-scooters-mopeds","title":"Main Jet #103 for SI Carbs for Scooters \u0026 Mopeds","description":"\u003ch2\u003eMain Jet #103 for SI Carburetors in Scooters and Mopeds\u003c\/h2\u003e\u003cp\u003eThe Main Jet #103 is a precision part used to tune SI carburetors on scooters and mopeds. This small, cone-shaped piece regulates fuel delivery from the main jet stack. It suits a range of engines and is commonly chosen for vintage Vespas, which generally call for jets within the 85-116 range. You can browse more \u003ca href=\"\/collections\/scooter-carburetors\"\u003ecarburetor parts and jets\u003c\/a\u003e that play a direct role in how an engine runs and how much fuel it uses.\u003c\/p\u003e\u003ch3\u003eHow It Works and What It Does\u003c\/h3\u003e\u003cp\u003eThis jet sets how much fuel reaches the combustion chamber. Higher numbers pass more fuel, so the size you choose has a direct effect on flow. Many riders try several sizes to find the best setup, particularly on modified engines that often need larger jets to get enough fuel through.\u003c\/p\u003e\u003ch3\u003eFitting and Tuning\u003c\/h3\u003e\u003cp\u003eTo swap it in, take out the current jet and seat the new one in the same spot. Basic hand tools are enough for the job. Dialing in the right size often takes some testing, so plan on trying a few options before settling on the one that performs best.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize:\u003c\/strong\u003e 103\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePosition:\u003c\/strong\u003e Main jet stack\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e SI carburetors for scooters and mopeds (main jet stack, #103 size)\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eCompatibility\u003c\/h3\u003e\u003cp\u003eFits:\u003c\/p\u003e\u003cul\u003e\u003cli\u003eSI carburetors (main jet stack position, size 103)\u003c\/li\u003e\u003c\/ul\u003e\u003cp\u003e\u003cstrong\u003eChoosing a size:\u003c\/strong\u003e Match the jetting to your engine. Most vintage Vespas run in the 85-116 range, and finding the ideal size takes trial and error.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eBrowse further:\u003c\/strong\u003e \u003ca href=\"\/collections\/scooter-carburetors\"\u003eScooter Carburetors \u0026amp; Jets\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":51138457960505,"sku":"TT-25699","price":4.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0665\/3358\/9049\/files\/main-jet-103-for-si-carbs-1.jpg?v=1794375348","url":"https:\/\/www.trendtimes.com\/products\/main-jet-103-for-si-carbs-for-scooters-mopeds","provider":"Trend Times Toy Stores","version":"1.0","type":"link"}