Why does a Snowblower Backfire?
You might like to own one of the many snowblowers out there. You can order them online and they are really useful during the winters to clear away the driveways. They do not cost a lot too and can be easily set up. With winters almost here, it is time to get ready for all that snow and take out your snowblower from the garage. However, one of the problems often faced by people after a long time of not using a snowblower is that it backfires. Why does this happen? More importantly, what can you do to remedy it?
Why is it backfiring?
If your snowblower is backfiring, the problem can be traced back to one of three reasons. The first one is running too lean. This could be caused by many reasons, for example, by a partially blocked orifice in the carburetor. The second issue could be incorrect timing (this could be about the valve or the spark); and the third issue that could be causing the backfire is the inlet valve not seating correctly. The inlet valve could also be damaged in any other way, like because of being partially burnt out.
What you can do about it
First, you need to make sure that the backfiring is not because of a lean fuel mixture. This can often happen if you leave old gas in the carb for a long duration (since last winter, presumably). Try to avoid doing this. But if you do leave fuel sitting in your carb, you need to treat the gas with a fuel stabilizer. There are a variety of them available – the two most popular ones are Seafoam and Sta-Bil.
1. Replace The Gas
First of all, replace any gas that may be remaining with fresh oil. Add a fuel stabilizer to this, but be careful to follow the instructions provided on the label. You could add a bit extra for the cleaning process.
2. Close the Choke
Next, make sure the choke is closed and run the engine. Keep it running for a while. The purpose of this is to let the fuel stabilizer clean out any carb passages that may have been partially blocked.
3. Clean the Carb Throat
Now you need to clean the carb throat. For this, use a carb cleaner spray and spray it down the carb throat. Finally, open the choke and test if the snowblower is any better.
What else can you do?
In case this fix doesn’t work for you, you will have to clean the carb very thoroughly or even rebuild it. Remove the bowl and use the carb cleaner spray to clean any internal passages that might be causing a problem.
Depending on your carb type (there are two kinds – most have two screws – for idle mixture and for high speed rev limit), while some have only one. This may need to be adjusted, and the adjustment will be assisted by the user manual that came with your snowblower. You can instead also take it to a local repair centre or a small engine shop for the adjustments.