Snowblower: Engine Will Idle But Dies At Full Throttle

The springs on the carburetor allow the butterfly valves to operate correctly, as well as the governor. Without these parts functioning, it will be impossible for engine on your snow blower to run and perform properly. A broken, missing, or poorly installed spring can affect carburetor function. You will need to the check owner’s manual for the correct routing of these springs. Ensure they are installed correctly, and replace any broken, weak, or missing springs.

The carburetor in your snow blower mixes the air and fuel together to form the proper mix for combustion. If the fuel/air mixture is not correct, your engine will not run properly, or it might not run at all. The following is a guide to adjusting your carburetor for peak performance, if you’re looking for a guide to breaking down, servicing, and reassembling your carburetor, see the “Carb Kit” heading elsewhere on this page. Locate the carburetor underneath the air filter, remove air cleaner cap, and look for any obstructions in the way that could block air flow, which would starve the engine of oxygen. Check for any adjustment screws – sometimes adjusting these settings to clean out the fuel flow will solve the problem. Locate both idle screws on carburetor, one marked L (low) and one marked H (high). You should turn both screws in, and this will shut off fuel. Then loosen each screw by about two full rotations, and try to start your engine. It may not run very smoothly or very well, but it should start at these settings. Let the engine idle for five minutes; this will bring the engine up to operating temperature. You can then turn the L screw clockwise to add more fuel to set idle, and at full throttle turn the H screw clockwise to set high idle. When you have the engine running at its, best you’re done. Please note this does require some experience and may take a few tries to get it right. Some snow blower models will have fixed carburetors, meaning they have no adjustments.

You can find the air filter on top of the carburetor. It cleans the air flowing into the engine, which prevents any small particles or debris from damaging internal engine parts. Over time and with extended use, the filter will start to clog. When that happens, it will need to be replaced, as the clog will be starving the engine of air and power. Locate the air filter cover on your snow blower engine and remove it. Please note, it may be attached by screws or just a tab. Once the cover has been removed you can pull out the existing filter, replace it with a new one, and reassemble. This should be part of the regular maintenance routine for your snow blower, and will help your snow blower engine perform at its best, and prevent problems in the future.

The fuel filter is located between the fuel tank and the carburetor on your snow blower. It prevents debris from entering the carburetor, which could cause major engine damage. If the filter is clogged it might be starving the engine of fuel while it is at full throttle. To check the fuel filter, gently twist the fuel line off both ends and blow through it. There may be an arrow on it indicating the direction the fuel flows in. If it is blocked or you suspect it is partially blocked, it is time to replace the fuel filter. We do recommend that this be done as part of regular maintenance.

The gasket seals the connection between the carburetor and your snow blower. The seal prevents air and fluids from entering areas where they are not supposed to go. A damaged gasket below a carburetor will pull excess air into the engine, causing the air fuel mixture to be wrong, and causing your engine to lose power and stall out. To check this, start by removing the air filter, then loosen carburetor bolts. Once you have the gasket out, you should inspect it for tears or rips, or any indications of leaks. Gaskets can only be used once, so regardless of its condition it will need to be replaced.

The spark plug in your snow blower is responsible for igniting the fuel/air mixture that is flowing into the combustion chamber. To check your plug, you need to remove the wire from spark plug – be very careful when doing so, as they are fragile. Remove the spark plug and check its condition. Sometimes a good cleaning and re-gapping to the manufacturer’s specifications can solve this problem. If you cannot clean and restore your spark plug, you will need to replace it. If the engine runs at high RPM a lot of the time and under load, then you will require a cooler running plug, which will work to dissipate heat.

The needle valve is located inside the carburetor bowl, and it regulates the amount of fuel entering the carburetor. It is not uncommon for a small particle of debris to get in it, which can disrupt the flow of fuel. We recommend you read through the repair help for “Carb Kit” on this page. This will walk you through how to disassemble, clean, and reassemble the carburetor in your snow blower to resolve this problem.

A carburetor kit has everything you need to tear down and rebuild the carburetor in your snow blower. It is a great way to extend the life of your carburetor, as it essentially restores your carburetor to new condition, which will help keep your engine 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 reassemble it at the end. We also recommend you lay all of the parts out in the order you took them off, which will make reassembly much easier as well. All snow blowers are a little different, depending on manufacturer and model, so the process will vary slightly. With some models, the carburetor is already exposed, if yours is, skip the instructions that are not relevant to you. If necessary, start by removing any covers or shrouds around the carburetor. You may need to remove the handle bar on some models to pull off the covers. Remove any knobs, disconnect any switches and fuel lines on the primer bulb. You will then need to remove the cover that houses the knobs, switches and primer bulb. Remove the choke lever carefully. Make sure you pinch off the fuel line to prevent fuel from leaking out of your snow blower. Remove the fuel line and slide the choke control plate off the carburetor, and disconnect the linkage from the control plate and carburetor. Disconnect the throttle rod return spring, and remove the throttle rod from the carburetor. You should now be able to slide the carburetor right off. Take it over to a workbench and start disassembling it. First remove the nut on the bowl, and then remove the bowl and gasket. Next, remove 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 the metering plug out of the carburetor. You should now spray the carburetor, fuel bowl, and all the small orifices with carburetor cleaner then carefully wipe it all clean. Inspect the carburetor and all the components for any signs of damage. If there is any corrosion inside the carburetor it will need to be replaced. Now you need to put everything back together. Start that process by installing a new emulsion tube, and new main jet. Make sure those parts are secure, then firmly press the new metering plug into place. Reinstall the throttle stop screw; this should be screwed in until approximately 1/16 of an inch sticks out the other side. Place 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. Install a new O-ring on the bowl before reinstalling. After you have completed the rebuild you can then reinstall the carburetor and the gasket onto the engine. Reattach the throttle cable and fuel line, and unpinch the fuel line. Reinstall the cover that houses all the knobs, switches, and primer bulb, making sure you hook everything back up. Reinstall all the covers and shrouds and the handle bar.