Re: Runs great with Choke!!!!
If the leaf valves were faulty, you would have fuel being spit out the front of the carburetor throat with every downward thrust of the piston. Obviously you do not have that problem.<br /><br />The fact that the engine picks up rpms and improves the performance when the choke is accuated indicates that you have overlooked something within the carburetor.<br /><br />Remove and dismantle the carburetor. Manually clean the fixed brass high speed jet that's located in the bottom center of the float chamber with a piece of single strand wire. Don't just assume it's clean because it may have been soaked in carburetor cleaner.<br /><br />There may be a small brass tube within the larger high speed nozzle. That smaller tube is supposed to be off center. Do not attempt to straighten it. Make sure that tube is also clean.<br /><br />When assembling the float chamber to the upper body, make sure that the small gasket is installed that surrounds the high speed nozzle tube.<br /><br />The throttle butterfly roller must be adjusted so that the butterfly just starts to open when the roller is aligned with the scribe marks on the cam. If the butterfly opens before aligning with those marks, the engine will die out.<br /><br />In gear (engine not running), throttle set to full throttle so that the vertical throttle arm is full against its stop, adjust the brass clevis set screw so that the rod has the butterfly perfectly horizontal to its full throttle position.<br /><br />(Carburetor Adjustment - Single S/S Adjustable Needle Valve)<br />(J. Reeves)<br /><br />Initial setting is: Slow speed = seat gently, then open 1-1/2 turns.<br /> <br />Start engine and set the rpms to where it just stays running. In segments of 1/8 turns, start to turn the S/S needle valve in. Wait a few seconds for the engine to respond. As you turn the valve in, the rpms will increase. Lower the rpms again to where the engine will just stay running.<br /> <br />Eventually you'll hit the point where the engine wants to die out or it will spit back (sounds like a mild backfire). At that point, back out the valve 1/4 turn. Within that 1/4 turn, you'll find the smoothest slow speed setting. <br /> <br />Note: As a final double check setting of the slow speed valve(s), if the engine has more than one carburetor, do not attempt to gradually adjust all of the valves/carburetors at the same time. Do one at a time until you hit the above response (die out or spit back), then go on to the next valve/carburetor. It may be necessary to back out "all" of the slow speed adjustable needle valves 1/8 turn before doing this final adjustment due to the fact that one of the valves might be initially set ever so slightly lean.<br /><br />When you have finished the above adjustment, you will have no reason to move them again unless the carburetor fouls/gums up from sitting, in which case you would be required to remove, clean, and rebuild the carburetor anyway.<br /><br />Now..... what are you going to do the rest of the day? (grin)
