Snowblower: Engine Rpm's Surge Up And Down

There are springs on the carburetor that allow the butterfly valves to open and close properly. The springs also ensure the governor is operating properly. If the springs are losing elasticity, or if they are broken, you may find that the engine on your snow blower is not preforming properly. A broken, missing, or badly installed spring can affect carburetor performance. Check model-specific diagrams and manuals for the proper routing and installation of these springs with your snow blower. Make sure each spring is installed correctly and replace any broken, weak, or missing springs. Removal and installation of springs can be done carefully with pliers. Do not bend these springs, as it will impact operation.

The carburetor mixes the fuel and air together to form the proper mix for combustion inside the engine of your snow blower. If you do not have the proper mix of fuel and air your engine might run rough, or it might not run at all. Every model will be different, so for the first stage of this repair you will need to locate your carburetor. To access to the carburetor, you will need to remove any covers or heat shrouds that are in the way. To adjust the carburetor settings, locate both idle screws on the carburetor, one marked L (low) and one marked H (high). You will first want to shut off the flow of fuel into the carburetor, so thread both screws in all the way. You will want to loosen the screws by roughly two full turns each. After you have loosened them you need to next start your snow blower. It may not run very smooth but it will start with these settings. Let the engine idle for a minute, then turn the L screw clockwise to add more fuel. This will help you to set idle. Next, at full throttle, turn the H screw clockwise to set high idle. When you have the engine running at optimal levels, you are done. This does require some experience, and it may take someone without a lot of prior knowledge a few times to get it right. Adjust the governor screw by locating it on your carburetor. Its location will vary depending on model. Loosen the bolt on the governor screw, then turn the screw slightly to get the engine to run around 3400 – 3600 rpm. There are some carburetors, know as fixed carburetors, that you cannot adjust.

Air filters send clean-flowing air into the engine. They prevent small particles of dust, dirt, and debris from damaging the inside of your engine. When the air filter on your snow blower becomes heavily soiled or clogged it will starve the engine of oxygen, which will lead to poor engine performance. Air filters should always be replaced as part of your regular maintenance routine. To replace your air filter, locate the filter cover and remove it. It may be attached by screws or just a tab. Once the cover is off and the filter is exposed, you can remove the old one, replace it with a new one, and reassemble.

The gasket seals the bap between the carburetor and the engine. The seal is so tight that it prevents extra air from entering the engine, which would cause the air fuel mixture to be lean. Over time this gasket might wear out or break down. Once you remove the gasket for inspection, you will need to replace it, you can not put a used gasket back onto you snow blower. It will not seal the gap as efficiently. Start by removing all covers and heat shrouds in order to gain access to the carburetor. In some cases, you may have to remove the handle bar. Loosen and remove the bolts holding the carburetor onto the engine and to the air intake. Remove fuel line, making sure it’s pinched off to prevent a fuel leak. Remove throttle linkage if needed. Check gasket for damage or leaks, and replace it with a new gasket, and reinstall the carburetor.

A carburetor kit has everything you need to take apart, clean, and rebuild your carburetor. It is a great way to extend the life of your carburetor, and ensure that your engine is running smoothly. When rebuilding the carburetor, it’s a good idea to take pictures of all the parts as you take it apart so you know where they go when you are putting it back together. Once you access and remove the carburetor you can get to work. Start the disassembly by removing the nut on the bowl, then remove the bowl and gasket. Pull out the float pin and float valve. Unscrew the main jet screw and dump it out with the emulsion tube. Remove the plastic throttle stop and pull the metering plug out of the carburetor. Use carburetor cleaner to spray the body, fuel bowl, and all the small orifices, then carefully wipe each piece clean. Look for any signs of corrosion inside the carburetor and the bowl, if you find any the carburetor will need to be replaced. Now you can start putting your carburetor back together. Install a new emulsion tube and new main jet. Firmly press a new metering plug into place, and reinstall the throttle stop screw. It should be threaded until it sticks out the other side about 1/16 of an inch. Put a new spring on the needle valve, and snap the new needle valve into the new float. Reattach the float to the carburetor with the new pin. Put a new O-ring on the bowl before you install it and tighten it into place. Once you are finished the re-build you can reinstall the carburetor and gasket onto the engine.