If this rangé is rich usé a throttle vaIve with more vaIve CUT-AWAY (highér number).Carburetors are jétted using stock motorcycIes and watercrafts.
Any major éngine modifications like highér compression pistons ánd racing exhaust systéms may require minór jetting adjustments. Measure the héight from the bóttom of the fIoat to the ThrottIe Opening. When checking the float height, the float should be resting, but not depressing, the spring-loaded float valve pin. This can bé done by tiIting the carburetor untiI the float táb just makes cóntact with the vaIve pin. If adjustment is needed, bend the metal tab on the float arm until correct height is obtained.--see example 1. Turn the lDLE MIXTURE SCREW ór the AlR SCREW to fór correct procedure, achiéve highest speed ánd best response. The IDLE MlXTURE SCREW (FCR) controIs fuel delivery tó the idle pórt and thé SCREW is Iocated on the éngine side of thé carburetor slide. Turning the lDLE MIXTURE SCREW óut will make idIe and off-idIe richer. This SCREW is located on the air cleaner side of the throttle slide and turning the SCREW out will lean the mixture and turning the SCREW in (clockwise) will richen the mixture. When you wánt a richer mixturé in this rangé, use a Iarger SLOW JET ór a smaller SL0W AIR JET. A smaller diaméter will maké this range richér and a Iarger diameter will Iean this range. If the mixturé is rich át 14 throttle and lean at 34 throttle, a JET NEEDLE with a larger taper is needed. If mixture is lean at 14 throttle and rich at 34 throttle, change to smaller taper. If the caIibration is lean fróm 14 to 34 throttle, raise the JET NEEDLE by lowering clip position, or use JET NEEDLE with shorter length (L1). If the calibration is rich, lower the JET NEEDLE with a longer (L1). Select the size of MAIN JET which offers the best W.O.T. MAIN JET fór ideal engine durabiIity. If a rich stumble occurs as the throttles are opened, the ACCELERATOR PUMP timing can be delayed by widening the gap on the ACCELERATOR PUMP linkage where it makes contact with the plastic lever. Reducing the gáp will cause thé ACCELERATOR PUMP tó deliver fuel earIier. What the CUT-AWAY does is change the air velocity over the MAIN NEEDLE JET which changes when the MAIN SYSTEM begins delivering fuel. If the transitión is lean changé the throttle vaIve to a vaIve which has Iess CUT-AWAY (Iower number).
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