| If the mixture screw has been reset by the dealer or previous owner (evident by the plug already being removed), turn the screw clockwise until it seats. Now turn the screw outward 2 turns to establish a starting point. The same procedure applies if using an EZ-Just screw. Reinstall the carburetor back on your bike by reversing the steps taken during removal. Be sure to replace the fuel hose clamp and vacuum lines. It may be a matter of dexterity but I prefer to install the cables before pushing the carb back onto the manifold. Make certain the carb firmly seats back onto the manifold boot. Test the throttle for binding and smooth operation. Double check each hose and connection. The air cleaner assembly MUST be installed prior to starting the engine, not only to hold the carburetor in place but to prevent having the carb backfire in your face while tuning. Start the engine as normal and bring up to operating temperature prior to fine tuning. Let the bike idle for no more than 5 minutes. The modified carburetor should allow your bike to run well enough for a mild test run around the block to speed up the warm-up process. With the engine warmed up and at idle you may now fine tune the idle mixture screw for optimal performance. Acquainting yourself with the adjustment screw location at the bottom rear of the carburetor prior to running the engine is advised, which also prevents burning your hands. You will need a small screw driver for adjusting the screw unless an EZ-Just has been installed. With the engine idling slow (no more than 900 rpm), turn the screw inward (clockwise) SLOWLY until the engine starts to stumble. You are working with the screw upside down so check to make sure you are turning the screw clockwise or inward. Note: Be careful not to allow the screw to fall out as there is a very small spring, washer, and o-ring that will fall out as well. These items known as the mixture screw packing are not available from the dealer or manufacturer, however if you should lose these parts there is an aftermarket replacement kit available. Contact for availability. If the engine will not idle on its own during this procedure, adjust the idle set screw on the throttle side of the carburetor until it idles correctly. Now turn the mixture screw outwards (counter-clockwise) until the engine begins to run smoothly, then add 1/8 of a turn. Maintain proper idle speed and repeat the adjustment each time you adjust the idle speed. Blip the throttle a couple of times and observe the results. If the engine responds quickly with a smooth blast and no backfiring through the carburetor, you have your idle mixture right. If backfiring occurs through the carburetor then adjust the idle mixture screw out another 1/8 turn. Normally, the mixture screw should only require 2 to 3 turns. Anything above 4 turns indicates the pilot jet is too small. |