Snowblower runs rough: Common Causes & How to Fix
1Snowblower Spark Plug
Most Common Solution
Repair Instructions:
Take a close look at the spark plug to see if it is worn down or damaged. Check if the porcelain insulator part has any cracks, the electrode metal tip is burned away or harmed, or there is a lot of carbon buildup at the electrode. If you notice any of that, you'll want to replace the spark plug with a new one. You can also use a spark plug tester tool to check if the plug is bad. When you're cranking the engine over, there should be a strong spark jumping between the tester terminals. No spark means the spark plug is defective and needs replacement. A good spark shows the plug is still working properly.
How to Replace Snowblower Spark Plug
- Make sure the engine is completely cooled off before starting. This ensures you don't burn yourself on hot engine components.
- Locate the spark plug. It is usually easily accessible once you lift the cover or remove panels on the engine housing. Refer to your owner's manual if needed.
- Disconnect the spark plug wire by grasping and pulling on the rubber boot, not the wire itself. This will allow you to remove the plug.
- Use a spark plug wrench to loosen the plug by turning it counterclockwise. If you don't have a wrench, a socket of the proper size will also work.
- Remove the old spark plug once loosened and inspect it. Look for damage like cracks or excessive wear. This can indicate issues with the engine.
- Check the spark plug gap of the new plug using a gapper tool. Adjust it to the proper measurement if needed. Refer to your manual for the right gap size.
- Carefully insert the new plug, being sure not to cross-thread it. Tighten with the wrench to the torque spec in your manual.
- Reattach the wire to the spark plug. Make sure the connection is snug.
- Start the snowblower and allow the engine to warm up. Make sure it is running properly before using the machine.
2Snowblower Carburetor
Most Common Solution
Repair Instructions:
The issue could be that the carburetor has gotten clogged up. This usually happens when you leave fuel in the snowblower for a long time. Over time, some of the ingredients in the fuel can evaporate, leaving a thicker, stickier substance behind. This sticky fuel can plug up the carburetor and make the engine run rough. To fix it, try using carburetor cleaner to unclog the carburetor. Spray it in there and let it sit to break down the gunk. If cleaning it out doesn't work, you'll probably need to rebuild the carburetor entirely or just replace it with a new one. Leaving old gas in is a common cause of carburetor clogs, so if your snowblower engine is running poorly, inspecting and cleaning the carburetor is a good place to start. A rebuild or replacement may be needed if it’s too gummed up.
How to Replace Snowblower Carburetor
- Disconnect the spark plug wire to prevent accidental starting of the engine.
- Drain the old gas from the fuel tank and lines into an approved container. This will prevent gumming up the new carburetor.
- Remove the air filter to allow access to the carburetor.
- Detach the throttle linkage from the carburetor using pliers.
- Loosen the carburetor bolts and carefully remove the old carburetor. Be prepared for residual gas to leak out.
- Transfer any carb gaskets or spacers to the new carburetor if they are in good condition.
- Install the new carburetor with the bolts and gaskets. Do not overtighten.
- Reattach the throttle linkage and air filter to the carburetor.
- Add fresh gas to the tank and check for leaks at the connections.
- Reconnect the spark plug wire and start the engine to test for proper functioning. Make adjustments to the carburetor as needed.
- Allow the engine to warm up before subjecting the snowblower to heavy use. Monitor performance.
3Snowblower Carburetor Repair Kit
Most Common Solution
Repair Instructions:
The issue could be that the carburetor has gotten clogged up. This usually happens when you leave fuel in the snowblower for a long time. Over time, some of the ingredients in the fuel can evaporate, leaving a thicker, stickier substance behind. This sticky fuel can plug up the carburetor and make the engine run rough. To fix it, try using carburetor cleaner to unclog the carburetor. Spray it in there and let it sit to break down the gunk. If cleaning it out doesn't work, you'll probably need to rebuild the carburetor entirely or just replace it with a new one. Leaving old gas in is a common cause of carburetor clogs, so if your snowblower engine is running poorly, inspecting and cleaning the carburetor is a good place to start. A rebuild or replacement may be needed if it’s too gummed up.
How to Replace Snowblower Carburetor Repair Kit
- Disconnect the spark plug wire to prevent accidental starting of the engine.
- Remove the carburetor from the engine by detaching all linkages, hoses, and fasteners. Follow your owner's manual instructions.
- Remove the carburetor bowl by taking out the screw on the bottom. Be prepared for gas spillage.
- Dump out the old carburetor parts and clean the bowl thoroughly.
- Install the new needle valve, floats, gaskets and any other parts provided in the repair kit. Use the instructions in the kit.
- Adjust the float height per the kit instructions to make sure fuel flow is set correctly.
- Reassemble the carburetor with the new components. Make sure all gaskets are in place.
- Double-check that all linkages are connected before reinstalling the carburetor on the engine.
- Install the carburetor using the proper torque on all fasteners.
- Reconnect the spark plug wire and test the snowblower, making any additional carb adjustments as needed.
- Allow several minutes of warm-up before high speed operation to ensure proper carburetor function. Monitor performance closely.
4Snowblower Engine Oil
Common Solution
Repair Instructions:
The issue could be that there is too much engine oil in there. If you overfill the engine oil, it can leak out through the breather and get into the carburetor. When oil seeps into the carburetor, it gums things up. To fix an oil-soaked carburetor, take the carburetor off and clean it really well to remove all the oil. Make sure to check the oil level in the engine after putting the cleaned carburetor back on. You want the oil at the proper fill line on the dipstick - not low but not overfilled either. Too much oil is probably what caused it to leak through in the first place. Keeping the right oil level will prevent leaks into the carburetor. So if you notice oil getting into the carb and making the engine run rough, a carburetor cleaning and oil level check is needed to fix the issue.
How to Replace Snowblower Engine Oil
- Run the engine briefly to warm up the oil so it will drain easily. Be sure to shut off the engine and allow time to cool before draining.
- Locate the oil drain plug, often on the bottom of the engine near the dipstick. Place an oil pan underneath.
- Use a wrench to remove the drain plug and allow the old oil to completely drain out.
- Replace the drain plug once oil has finished draining. Be sure it is on securely.
- Unscrew the oil fill cap and slowly pour in new oil of the correct weight and amount per your owner’s manual. Most engines take 20-24 oz.
- Use a funnel to prevent spills and allow time for oil to fully settle into the engine.
- Replace the oil fill cap once the proper amount of oil has been added.
- Start the engine and let it run briefly to circulate the new oil. Check that the oil level on the dipstick reads full.
- Properly dispose of the old drained oil at a recycling center. Used oil is hazardous to the environment.
- Recheck oil levels periodically to ensure optimal engine lubrication. Change oil again after recommended hours of operation.