Initial Metering Rod Setting

The best way to achieve initial setting is to use a fuel ratio tool, this tool will actually measure the taper of the metering rod at an idle position. The fuel ratio tool is available for purchase please contact Lectron® fuel systems. If you do not have the fuel ratio tool you can achieve an initial setting using a set of veneer calipers to measure from the tip of the rod to the brass insert in the slide.

  Note: Flat Side of Metering Rod Must Always Face in Towards Engine

            The metering rod that is supplied with your carburetor is recommended for a standard serial production version on your engine, in its normal state of tune. Any variations of tuning beyond the way that your engine was manufactured and subsequently maintained will effect the recommended selection and or setting of the metering rod.

          For fine LOW END tuning, turn the metering rod in direction of Arrow "A" (richer) or "B" (leaner) as shown in FIG. 2 and rotate until flat side of rod is in position as shown.

         

When tuning Lectron® Carburetor there just 3 basic steps you need to achieve. Although when you purchase a new carburetor form us it is pre-set there are some variables in tuning.

Idle adjustment:

Start engine and try to get it up to operating temperature. Adjust the Carburetor with idle screw to achieve a good stable idle about 1500-2000 rpm., at this point give the throttle a couple of twists to check the response. If the engine seams to gurgle or stutter during acceleration it’s probably to rich, and if seams to wander or rev. out of control it’s probably to lean. When this condition occurs observe the slide cutaway, if the cutaway is open a lot the rod is probably rich, and if the cutaway is small it’s probably lean. To achieve proper air fuel ratio you need to adjust the rod. Remove the three screws from the top of the Carburetor and remove the slide and rod assembly. To richen the rod you need to make the rod shorter, and longer to lean out. Take a pair of needle nose pliers and turn the rod in to shorten or out to lengthen. To make a ¼ turn adjustment turn the rod one ¼ turn with the pliers DO NOT PUSH UP ON THE ROD, now that you have turned the rod ¼ turn the flat side of the rod does not face toward the engine any more, you must now adjust the rod so it does. Use your fingers to achieve this adjustment, simply grab the rod with your fingers and push up on the rod till you feel it bottom and spin it back so the flat side of the rod faces the engine and then it drop down, you are done you have made a ¼ turn adjustment. You can make as many adjustments as you want from ¼, ½, ¾, or full turns to achieve the proper fuel ratio.

 

          When working with two or more carburetors, it is necessary to measure the length of each metering rod from the brass insert to end of rod, to make sure they are all in at exactly the same length. If the rods are not equal, cylinders will run either too lean or too rich at idle. Again the most precise way to archive proper fuel for each cylinder is to use the fuel ratio tool.