Disassembly
Most carburetors on Craftsman mowers are variations on a common float design. Newer mowers tend to have no adjustments and no choke - which greatly simplifies cleaning and adjustment. With respect to adjustment, there is none - it either works or it doesn't. If it doesn't, your cleaning was not thorough enough, some parts need replacement, or the problem is not in the carburetor.IMPORTANT: Before removing any linkages or springs, make detailed diagrams as to how everything goes together. You will NOT remember this several hours later!!! Reassembling the linkages EXACTLY as your found them is critical to the happiness of your engine.
- Under the bowl is a large hex head bolt. On the non-adjustable carburetor, this is closed on the bottom. It is also not a simple bolt but includes the precision main fuel metering hole which will need to be cleaned thoroughly. Use a proper socket to unscrew this bolt (counterclockwise). Drain any residual gas from the bowl. CAUTION: I've heard of people breaking the bolt by either attempting to loosen it the wrong way or overtightening upon reassembly to stop leaks.
- There is a fiber washer under the bolt. There may also be a fiber washer on this nut inside the float bowl. Don't lose these or get them mixed up.
Turn the carburetor upside-down.
- Carefully remove the bowl and O-ring. Inspect these for damage. (Note: there is probably a dimple in the bottom of the bowl in the lower level side. This is normal and probably there to keep the float off of the bottom where gunk and varnish collect because you didn't drain the gas.)
- The float will now be visible. Rotate it to the fully up position. The inlet needle will come up with the hinged part of the float. It is held in place by a wire clip but will now be free. The inlet needle is actually a four sided metal rod with a polished conical tip. Remove the needle and clip.
- Use a pair of needlenose pliers to pull out the hinge pin which will free the float. Careful - the float is made of relatively thin brass and is susceptible to damage.
Check the throttle plate for free movement - there should be absolutely no hint of binding or tightness. If there is, then this will need to be disassembled as well and cleaned:
- Use an open-end wrench to loosen the intake pipe and then remove the nuts and bolts. The manifold will probably come free with the gasket intact. Don't lose the metal strip to which the governor spring attaches. Check for dirt and other debris and set aside.
- Use a 1/8" straight blade screwdriver to remove the screw in the center of the throttle plate. Note the position of the hole in the plate and the orientation of the plate. (The hole should be toward the engine side with the carburetor body upright. Mark it before removal if in doubt.)
- Tap the carburetor if needed to remove the throttle plate.
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Pull the throttle shaft out of the carburetor body. Take care not to lose the spring with the felt and/or metal washer. Note their positions.