How to Fix a Honda GCV160 That Won’t Stay Running

If your GCV160 motor starts, runs for 4-5 minutes then stops, I will explain to you why it’s happening and what you can do to fix it!

I will delve into it in more detail in the article but here’s a quick TL;DR – It’s most likely that either your Gas Cap is Clogged or Your Carburetor is Dirty/Clogged. Clean/Replace both of them and your GCV160 should be good to go!

If you need a more detailed diagnosis and Solution, keep reading!

Honda GCV160 Gas Cap Clogged

Modern engines, including the GCV160, use a vented gas cap. This design allows air into the fuel tank to replace the volume of consumed gasoline, ensuring a balanced air pressure.

Over time, however, these vent holes can become clogged with debris or dirt, which prevents air from entering the tank. The result? A vacuum forms within the tank, restricting the flow of gasoline to the engine.

Diagnosis – If you suspect the gas cap might be the reason for your engine shut down, try running the mower with the cap slightly loosened. If it continues to run without interruption, you’ve likely found the problem.

Once you’ve confirmed the gas cap is your problem, you can either try to clean the vents with a sharp object such as a sharp screwdriver, or you can buy a replacement.

Auto Choke Mechanism

Now, if you’ve ruled out the gas cap, or if loosening it didn’t change the outcome, you need to have a basic understanding of how the auto choke functions in the Honda GCV160.

The auto choke system, or the wax choke assembly in some Honda models, is pretty interesting in the way they work!

As the engine warms up, the wax inside the assembly expands, pushing a pin which, in turn, opens the choke valve.

This mechanism ensures that the engine gets more fuel initially than Air and then the choke valve opens us automatically after a long enough run time.

Usually, it takes about 4-5 minutes for the vax to warm up, and it is no coincidence if the engine is shutting off after 4-5 minutes as well!

But you would be wrong to assume that if your engine is dying out the choke must be damaged! Instead, you’re rather in the situation of your GCV 160 running only on choke! Because as soon as the choke goes out, your engine goes off.

But in case your choke doesn’t transition smoothly from its cold to warm state, the choke will remain in its cold state (closed) longer than it should, it could cause the engine to receive too rich a fuel mixture, which is also not good for the engine.

How to Check: With the air cleaner removed, start the engine and observe the choke’s operation. If, after warming up, the choke doesn’t open or does so unevenly, you may be on to something.

Carburetor Needs Cleaning

As I pointed out earlier, if your auto choke is performing as it should, and the engine shuts off as soon as the choke valve opens, then your carburetor needs to be cleaned!

Basically, what’s happening is that the carburetor is not able to intake the appropriate amount of fuel for the increased air coming in once the choke valve opens up!

This happens because the main jet is often filled with dirt. The process of cleaning the carb is pretty simple. Here you can find a video on how to do that –


In conclusion, while a Honda GCV160 engine is known for its durability, like all machines, it can have its off days. Whether it’s a clogged gas cap, a malfunctioning auto choke, or a dirt-filled carburetor, understanding the symptoms and causes will empower you to get your mower back to its grass-cutting glory.

And always remember, regular maintenance goes a long way in preventing these common issues. Mow happy!

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