{"product_id":"49mm-big-bore-nikasil-cylinder-piston-kit-for-stihl-ms311-ps-aq33-vaff","title":"49mm Big Bore Nikasil Cylinder Piston Kit for Stihl MS311","description":"\u003cp\u003eA 49mm Nikasil cylinder and piston kit for the Stihl MS311, taking the saw from its stock 47mm bore to 49mm. The kit contains the Nikasil-plated cylinder, a 49mm piston, piston rings, wrist pin and circlips. This is the 3-bolt intake version: these cylinders were built with both 3-bolt and 4-bolt intake manifolds, so count the bolts holding the intake to your old cylinder before ordering. It replaces cylinder assembly 1140-020-1204. If you want a straight repair at the original 47mm size, look for a 47mm MS311 piston instead. Before fitting, pressure and vacuum test the crankcase and replace hardened seals, a cracked intake boot or a split impulse line, since an air leak scores a new piston as fast as the old one. Use a ring compressor on assembly, and check the carburetor setting once the saw is run in, because the larger bore draws more fuel.\u003c\/p\u003e\u003cul\u003e\n\u003cli\u003e49MM BIG-BORE CYLINDER AND PISTON FOR THE STIHL MS311 - Takes the MS311 from its stock 47mm bore to 49mm. The kit holds a Nikasil-plated cylinder, a 49mm piston, rings, wrist pin and circlips.\u003c\/li\u003e\n\u003cli\u003eCOUNT THE INTAKE BOLTS FIRST - This is the 3-bolt intake version. These cylinders were made with 3-bolt and 4-bolt intake manifolds; count the bolts on your old cylinder before ordering. It does not fit a 4-bolt saw.\u003c\/li\u003e\n\u003cli\u003eWANT THE STOCK 47MM SIZE INSTEAD? - This kit changes the bore. For a straight repair at the original size, a 47mm MS311 piston is the part to look for.\u003c\/li\u003e\n\u003cli\u003eREPLACES CYLINDER ASSEMBLY 1140-020-1204 - The 49mm cylinder and piston assembly. If your parts list shows this number, match the intake bolt count before ordering.\u003c\/li\u003e\n\u003cli\u003eBEFORE THE NEW TOP END GOES ON - Pressure and vacuum test the crankcase and replace hardened crankshaft seals, a cracked intake boot or a split impulse line. A larger bore draws more fuel, so check the carburetor setting once the saw is run in.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Lil Red Barn","offers":[{"title":"Default Title","offer_id":68009656287386,"sku":"PS-AQ33-VAFF","price":159.95,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0397\/2346\/6909\/files\/71szRN-5QDL_f4ef1123-994d-481a-91c4-ddf1c3223eb9.jpg?v=1793383375","url":"https:\/\/performancesawsupply.com\/products\/49mm-big-bore-nikasil-cylinder-piston-kit-for-stihl-ms311-ps-aq33-vaff","provider":"Performance Saw Supply","version":"1.0","type":"link"}