How to Fix a Leaking Petcock Valve?

If you are an ardent fan of dirt biking with an ATV parked in your garage, you must be aware of the efforts required to maintain one. Yes, and All-Terrain Vehicles or ATV involves a lot of maintenance and, rightly so, because it steers upon the worst of trails non-stop. Of all the troubles you can encounter with your ATV, the most annoying one is a leak in the Petcock Valve.

What is a Petcock valve, and how does it work?

Before we proceed towards the technicalities about how can you fix petcock leaking, here is an introduction to this component of your ATV.

Essentially, a petcock valve controls the flow of fuel into the engine. So, if it is “on”, you can ride your bike. However, when it is “off”, you cannot ride the bike. There is another petcock valve position – “reserve” that allows you access to the fuel lying in the bottom of the fuel tank so that you can reach the next gas station without having to drag the bike. Also, if you want to use the carburetor as you ride, you can switch the valve to the “prime” position. In this position, the vacuum doesn’t work so that you can draw carburetor without turning the engine on.

For those wondering why there is a need for “off” position in a petcock valve, the answer is safety. Yes, it is always safer to cut the flow of fuel to other parts of the bike to prevent leakage or unwanted combustion. It is also beneficial when performing repair and maintenance work on the bike.

How to detect Petcock leaks?

fix petcock valve

The most effective way to detect leaking petcock is to witness it with your own eyes. Yes, when you see fuel dripping from your bike, sitting on top of its motor, or can smell gas around it; possibly the fuel is leaking from the petcock valve.

If you are still unsure, you can turn the petcock “off” and then check whether the fuel is still dripping. Even though you can ride your bike with a leak in the petcock valve, it is not such a great idea with a heated engine next to it. Such a situation can result in a blast.

Repairing the Petcock’s Seal

Source: Ichiban Moto

Once you know that it is the petcock that is leaking, you can perform the following DIY tricks to fix it and bring your bike back on tracks.

  • Drain the gas and remove the tank
  • Inspect the Petcock Valve for Damage
  • Replace the Seal

Drain the gas and remove the tank

Keep a clean bucket or gas container handy when draining out the contents of the carburetor so that you can remove the gas line and insert it into the bucket. Once you have created the setup, you can turn the petcock valve on and let the fuel flow out. If you are eyeing a more comfortable method, remove the gas quad from the vehicle and pour out the gasoline.

Then again, removing the gas tank can be a different struggle for different bikes since there are a lot of nut bolts and screws to be dealt with. Some of them aren’t even in the site when you are putting the tank back, resulting in a lose fix. Also, some of them require you to remove the air filter along.

Inspect the Petcock Valve for Damage

Now that you have increased the visibility by removing the gas tank, you can easily locate the source of the leak. To begin with, take out the petcock valve from the ATV and check the seal. You might witness some damage on the seal due to the aging of the ATV. So, 90% of the time it is the seal that is causing the leak. Then again, if you see no visible damage in the valve, then it is perhaps its insides that are damaged. It can be the gasket around the valve that is letting the gas escape and leak into the carburetor or through the front of the valve.

Replace the Seal

For replacing the petcock valve seal, you can either repair the existing one with an RTV sealing agent or invest in a new one. Well, valve seals are not much of an investment as they do not cost more than $10.

An RTV sealing agent is also something you can place your bets on as it is readily available in most auto parts stores around you. It is a common auto parts sealant which doesn’t let the gas, oil, and heat to pass through.

Follow the following steps for restoring the petcock valve seal:

  1. Take the old gasket out and clean the area where the gas tank and the valve meet thoroughly. This is important because if the mating region is not clean the chemicals attached to the opening may contribute to creating a leaky RTV seal which you do not want.
  2. Now, you are ready to apply the RTV seal around the valve to create a solid gasket seal. For this, you have to keep beading the sealant around the edge of the valve while making sure that there are no breaks in the seal that can cause leakage. Once you are done applying the sealant, you can smooth it out with the help of your finger.
  3. Once you have created the gasket, reconnect the petcock valve with the gas tank and fix the screws on it tightly. If there is any excess RTV, remove it with the help of your finger or paper towel and wait for at least 24 hours before filling the gas tank again.

After allowing the sealant to dry for 24 hours, it is the time to perform checks. You can now reinstall the gas tank and air filters back on to ATV. Fill in the gas and turn the petcock “on”. This will allow you to check for immediate leaks. Now let it sit for another hour and check again. Once you are satisfied with your job, wait no more and head out for the adventures waiting to happen!