Starting in mid-1969 the Amal Concentric carb received a jetting “update" to help with starting and smoother running for Triumph and BSA 4-stroke models (singles, twins and triples) This update consisted of a new needle jet, needle and a needle jet holder - below are the specs and part numbers of the “updated” 4-stroke parts. The fine tuning is still up to you. 2001 YAMAHA YZ250F JETTING. Main: 175. Pilot: 42. Needle: OBELP. Clip position: 4th from top. Fuel screw: 2 turns (1-1/2 stock) Leak jet: 95 (105 stock) 2002 YAMAHA YZ250F JETTING. This carburetor jet size chart shows you how effective each jet is at specific throttle levels. A Pilot jet is effective at idle speed up to 1/4 throttle(low-range). A needle jet is effective from 1/4 throttle to 3/4 throttle(mid-range). A main jet is effective from 3/4 throttle up to wide open throttle(top-end). Nanti kalau portal ini memberi langkah-langkahnya, dibilang mengajari burung terbang dan ikan berenang. Tutup baut setelan angin dengan memutar searah jarum jam sampai mentok. S etelah itu putar balik (turn out), 3 putaran untuk sebelah kanan dan 2,5 putaran kiri, “Yang dimaksud 3 putaran artinya itu sekrup enam kali berputar. Kalau 2,5 .

setting pilot jet dan main jet