Carburetor Troubleshooting: How to Do?

Carburetors are important in engines because they regulate fuel and air mixtures entering the cylinder. However, you can encounter carburetor issues if you have a small gasoline engine. Here are carburetor troubleshooting tips to help you fix any carburetor-related problems.

Carburetors are essential in an engine because they help regulate the air and fuel intake entering the cylinder chamber. Regulation of the air and fuel intake entering the cylinder controls the torque of an engine. You can find a carburetor in small machinery like lawnmowers because they are more efficient than injectors. Carburetors have several functional parts, which include the throttle valve, idling system, metering system, carburetor strainer, venturi, choke valve, float chamber, mixing chamber, and throttle return checker.

The arrangement of the functional parts of the carburetor may vary depending on the type of carburetor running your engine. However, it is common to encounter carburetor issues because it contains numerous functional parts. Below are carburetor troubleshooting tips that can help you fix a faulty carburetor.

Table Of Contents

The carburetor can fail to work probably because of various technical issues, thus making it one of the most challenging engine parts to troubleshoot. Below are the carburetor issues you can expect to find on any carburetor engine.

Fuel filter blockage results in slow/no fuel flow to the engine.
Fuel pump failure hinders fuel flow to the carburetor.
Leakage in the Manifold causes surges when the engine is running.
A faulty fuel solenoid prevents fuel flow.
A blockage in the fuel tank prevents fuel flow to the carburetor.
A tap leakage causes excess fuel consumption and presents a fire hazard.
A leakage in the fuel line causes excess fuel consumption.
A blockage in the carburetor prevents fuel flow to the cylinder, thus causing the engine not to run/start.
Air filter blockage causes the engine to run poorly and emit dark smoke via the exhaust pipe.
Cap blockage prevents fuel ventilation in the tank, thus sealing the tank and cutting off fuel flow to the carburetor.
Debris in the fuel causes blockage in the fuel line and clogs the carburetor.

Troubleshooting Tips for A Faulty Carburetor

The most effective way to troubleshoot carburetor problems is by categorizing them as cold/warm starting issues, cold/warm power issues, or poor performance issues. You can read more about troubleshooting a faulty carburetor below.

Troubleshooting Cold/Warm Starting Issues on A Carburetor

Symptoms of a cold/warm starting issue include the following:

The engine is cracking but fails to start when trying to start the engine.
The engine starts but soon chokes and dies after a few minutes.
The engine starts and increases the RPM when accelerating, but afterward, the RPM reduces before seeing black smoke in the exhaust.

Engine cracking but failing to start is a symptom of no gas in the carburetor, fuel pump failure, choke not closing, or a faulty choke linkage binding. You can use the Gas Shot Test to check for gas flow in the carburetor. Chances are you have a blockage in your fuel line if the engine starts and runs well after performing the Gas Shot Test. Engine starting and dying soon afterward is a symptom of a faulty choke in your carburetor.

You can check if the choke is closing on your carburetor to know if you have a defective choke system. Engine starting and increasing RPM before soon afterward reducing and emitting black smoke is a symptom of a faulty choke or incorrect configuration of the choke in your carburetor. You can use the Choke System Check to resolve the choke issue on your carburetor.

Troubleshooting Cold/Warm Power Issues on A Carburetor

Symptoms of a cold/warm power issue on a carburetor include the following:

The engine stalls after running for a couple of minutes.
The engine hesitates, stalls, stumbles, flat-spot, or dead-spot when you accelerate it.
The engine backfires and emits dark smoke when running.
The engine backfires/spits back and expels black smoke via the exhaust, even when idling.

One of the solutions for fixing a cold/warm power issue is cleaning the fuel bowl. Cleaning the fuel bowl on your carburetor can help remove any debris preventing fuel from flowing in your carburetor. The fuel bowl is usually behind the air filter, and you can clean it before checking the fuel line to ensure there are no other blockages.

The other solution is draining the fuel bowl if you have stale gas in your fuel tank. The option of draining and cleaning the fuel bowl prevents old gas from clogging the fuel passages in your carburetor. You can add a Fuel Stabilizer to your gas tank to keep the gas fresh (usually up to 2 years) whenever you plan to keep the engine in storage for a prolonged period.

Troubleshooting Poor Performance Issues on A Carburetor

Symptoms of poor performance issues on a carburetor include the following:

The engine consumes excess fuel when it is running.
The engine loses power whenever it is running.
The engine in your machinery emits black smoke via the exhaust whenever it is running.

The most efficient way to resolve poor performance issues is by removing the carburetor and cleaning it. You can use the user manual from your manufacturer to learn how to disassemble and assemble the carburetor on your engine.

Cleaning a carburetor requires a genuine engine cleaner/degreaser, cleaning rags, and a container for nuts and bolts. Lubricate the choke linkage binding when assembling the carburetor, and ensure you change the air filter. You should also check the fuel line for leakages or blockages to ensure everything is in tip-top shape.

Conclusion

You can troubleshoot and fix a faulty carburetor by following the above guideline. Troubleshooting a carburetor requires patience, a keen eye for spotting irregularities in engine parts, and an attentive ear for listening to irregular noises whenever the engine is running.

Carburetors are cheap, especially when dealing with small engines. You can purchase a new carburetor rather than clean an old one. A new carburetor offers more guarantees and saves you lots of time. You can also seek help from a professional mechanic if you get stuck while working on your carburetor.