Rebuilding a Lawn Mower Carburetor

A lawn mower carburetor is an important part that helps mowers function. A carburetor is the part in an engine that helps it work. By mixing the right doses of air with gas, the carburetor is responsible for the running of an engine in an automobile. The principle on which the lawn mower carburetor functions is not different from that of the car or bike carburetors, but these are smaller, less complicated and easier to rebuild at home, without the need of professional servicing.

Tools and Materials Needed:

  • Small pry bar
  • Lubricating gel
  • Cotton wool
  • Brush
  • 6 inch bolts
  • Swivel screws
  • Wrench

Step 1 - Parts

To rebuild the lawn mower, all the parts need to be detached from the set up and then examined for repairs. After each separate part is checked and dealt with, the carburetor can be set back into place. You need to know the parts present in a lawn mower carburetor which are, an air filter, choke valve, metering rod of the carburetor, float valve and nozzle.

Step 2 - Air filter

Right at the top part of the carburetor, there is the filter. Locate this and place a small flat prying bar at its base. Pry it up by applying gentle force, making sure that you do not end up breaking it. It comes off easily. In case there is rust on the filter it shall require a little more force. Take a thick bristled brush and rub vigorously on the area around the air filter. This is needed to remove any rust or layers formed that might damage the filter. If the filter is rust free, fit it back in place. If not, insert a new filter in the hole and press down till it fits snugly.

Step 3 - Valve

Using screwdriver, loosen the screw that holds the choke valve in place. Once the screw is out, you can see the areas in the valve where the screw was present. Take some lubricating gel and spread it evenly all along the portion. Now take a new screw and place it back in the place where the screw was removed from. Tighten with a screwdriver. Check if the valve is rotating smoothly by tapping, after applying the grease.

Step 4 - Metering Rod

See where the fuel supply unit is placed. Loosen the bolts that secure its side panels to open it up. You will see a thin rod inside called the carburetor metering rod. Using wrench, loosen the small bolt that holds the rod in place with the link inside. Once this is done, the metering rod falls free and you can take it out. Wipe the rod thoroughly using some cotton wool so that the grease layers and other residue are cleaned. In case the layers are stubborn, add an auto part cleaner to the cotton wool and wipe away. Now, apply some lubricating gel on the link to which the rod was connected. See that the link is moving without obstructions by giving it a gentle tap. Place the rod as it was before, after connecting to the link, and tighten the bolt, using the wrench. You may use a new bolt if needed.

Step 5 - Nozzle and Float Valve

There is a tiny nozzle for intake of fuel attached to the air filter. Take a thin brush with wire bristles and insert into the nozzle carefully. Clean the nozzle channel by wiping with the brush. Similarly, use the brush to clean and scrub the chamber where the floating valve is attached. See if the parts are rusted. If so, the valve needs to be taken out after loosening its bolt with wrench. Take a new valve and attach it using the bolt in the proper place. If there is no rust, clean with cotton wool.