{"product_id":"main-jet-91-for-si-carbs-for-scooters-mopeds","title":"Main Jet #91 for SI Carbs for Scooters \u0026 Mopeds","description":"\u003ch2\u003eMain Jet #91 for SI Carburetors in Scooters and Mopeds\u003c\/h2\u003e\u003cp\u003eThis #91 main jet controls how much fuel reaches the engine in SI-style carburetors used on a range of scooters and mopeds. It is a small, cone-shaped piece that sits at the bottom of the main jet stack. Like other components listed under \u003ca href=\"\/collections\/scooter-carburetors\"\u003escooter carburetors \u0026amp; jets\u003c\/a\u003e, it plays a real role in how well the engine runs. Because the jet size sets the fuel flow, it is an important part for anyone wanting to fine-tune their machine.\u003c\/p\u003e\u003ch3\u003eUnderstanding Jet Sizes\u003c\/h3\u003e\u003cp\u003eMain jets come in sizes from 82 to 165. Vintage Vespas generally run jets in the 85 to 116 range. Engines that have been modified for more power often need larger jets to supply the extra fuel they demand. A higher jet number lets more fuel pass through, so it can make a noticeable difference when tuning.\u003c\/p\u003e\u003ch3\u003eAdjusting Your Jetting\u003c\/h3\u003e\u003cp\u003eGetting the jetting right usually takes some testing and adjustment. Different scooters and mopeds can need different jet sizes depending on what has been changed and how they are ridden. For step-by-step jetting advice, it is worth checking a dedicated guide or blog. Adjusting the jet size can help balance the air-fuel mixture and make the ride smoother.\u003c\/p\u003e\u003ch3\u003eSpecifications\u003c\/h3\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eSize:\u003c\/strong\u003e 91\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003ePosition:\u003c\/strong\u003e Main Jet\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFits:\u003c\/strong\u003e SI-type carburetors, main jet size #91 (scooters and mopeds)\u003c\/li\u003e\n\u003c\/ul\u003e\u003ch3\u003eFitment\u003c\/h3\u003e\u003cp\u003e\u003cstrong\u003eHow to choose:\u003c\/strong\u003e Pick a main jet size that suits your engine's jetting. Sizes run from 82 to 165, and the #91 is one of the sizes within that span.\u003c\/p\u003e\u003cp\u003e\u003cstrong\u003eShop more:\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":51138485190713,"sku":"TT-25756","price":3.98,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0665\/3358\/9049\/files\/main-jet-91-for-si-carbs-1.jpg?v=1794375430","url":"https:\/\/www.trendtimes.com\/products\/main-jet-91-for-si-carbs-for-scooters-mopeds","provider":"Trend Times Toy Stores","version":"1.0","type":"link"}