I ran into a situation not too long ago where I discovered that the gas cap was stuck on my lawn mower. This left me having to come up with a way to remove the gas cap without causing any damage to my lawn mower and the gas tank. Here’s what I came up with to safely remove the stuck gas cap that I will definitely repeat if it ever happens again.
How to Get a Gas Cap Off a Lawn Mower If Stuck (3 Different Gas Cap Types)
The gas cap that was stuck on my lawn mower was a plastic screw-type (threaded cap) that attaches to a plastic gas tank. Since both the cap and tank are made of plastic, I knew that I had to be careful not to break anything. Here’s my favorite method to get the gas cap off my lawn mower.
Plastic Threaded Cap
The most important thing to getting the cap off is the tool you use. You are going to need to use a tool that is big enough to grip the cap with even pressure on all sides. I found the best tool to do this was a large pair of pipe grips, the type of pipe grip that is designed to grip a round object. Also, a pair of grips will firmly grip the gas cap and not crush it. The bigger the grip, the better it seems to work. The last thing you want to do is crack the neck of the gas tank.
Next on the list of tools is a shop rag to drape over the filler cap. I found that a shop rag increased the grip and also protected the cap. Once you have the tools to remove the stuck gas cap, you are going to need to use a particular method. Nothing fancy, just slowly, carefully, and keeping centered. By using the pipe grips, you are going to have a lot more leverage which is good for removing the stuck gas cap but also increases the risk of breaking something.
So, get a firm grip on the cap through the shop rag and try to turn the cap slowly. Try your best to turn the grips around the cap and use this spot as a center point. If you use a motion off-center, you’ll run the risk of breaking the tank. If you feel a lot of resistance or feel that the tank’s neck is bending, stop. Try to reposition the grips and try again. With some adjustment and patience, the stuck gas cap should come off with no trouble or breakages.
Metal Winged Stuck Gas Cap
Metal winged gas caps these days are much less common. To be honest, I’m not even sure that they are used on new lawn mowers. But a lot of us have older lawn mowers with metal gas tanks and metal winged gas caps. So, if your winged gas cap is stuck, you should use the same approach as removing a threaded plastic gas cap and using the same tools. Just remember that a winged gas cap unusually only needs to be turned half a complete turn.
Ratchet Safety Stuck Gas Cap
You will find this type of gas cap on larger lawn mowers, such as ride-on and zero-turns. They are similar to what you will find on a car. Once the cap has tightened enough, it will begin to click and turn without tightening. Getting this type of gas cap off after it is stuck is similar to removing a cap from a medicine bottle with a safety cap.
I’ve found that applying a downwards force while loosening the cap is enough to remove the stuck gas cap. The added friction of the downwards motion seems to be all that is needed. I haven’t found that any type of tool can help this process unless it’s completely jammed and you intend to break the cap off.
Tips to Prevent Your Gas Cap From Getting Stuck Again
After getting my gas cap stuck, I realized that I needed to investigate why it happened in the first place. Here are some tips that will help you avoid getting your gas cap stuck for a second time.
Plastic Thread Gas Cap Stuck on a Lawn Mower Tips
A plastic cap should go on easily and only need to be tightened lightly. Avoid over tightening your cap, as this can deform and damage the threads of both the cap and the tank.
Also, a plastic cap should go on without a struggle. If you find that it is hard to start tightening it, then you could be starting to cross-thread the cap. If this happens, stop. Remove the cap and try again.
Finally, inside the gas cap, you will usually find a rubber washer that forms the seal between the tank and the cap. Over time, these washers will compress or even fall out. If this happens, then you might find yourself overtightening the cap. Be sure to keep an eye on the washer and replace it as necessary.
Metal Winged Gas Cap Stuck on a Lawn Mower Tips
Metal winged gas caps also have an internal washer that serves the same purpose as those on a plastic threaded cap. Again, be sure to keep an eye on these and make sure they are not missing or damaged.
Additionally, you will want to make sure that the actual cap isn’t damaged. If you have one of these types of caps, then your lawn mower is probably old and has been around for quite some time. It‘s normal for the cap to become worn and a bit bent up. If this is the case, then try to straighten it out and make sure that it works correctly. If it feels difficult to use, then you could be close to getting it stuck.
Finally, I’d recommend keeping an eye out for any corrosion. The metal that these caps are made of will likely rust over time and make it hard to get them on and off. A quick spray of wd-40 every so often should keep the cap moving freely.
Ratchet Safety Gas Cap Stuck on a Lawn Mower Tips
Ratchet caps are usually pretty heavy duty, which is why they are used on bigger lawn mowers. But this doesn’t mean they are not going to get stuck every so often. My biggest tip is to only tighten the cap as much as it needs to be. By this, I mean you only need the cap to click once or twice. The clicking is the indication that the cap is tightened correctly. If you continue to tighten the cap while the cap is clicking, you’ll be over-tightening the cap and potentially heading towards a problem.
Another thing to look out for is again the rubber washer. Like the other types of caps, the ratchet cap has the same type of washer doing the same job. So, keep your eye on it and make sure it’s in place and in good condition.
Other Reasons You Can’t Get Your Gas Cap Off Your Lawn Mower
It’s not always a case of operator error or a damaged gas cap that will cause it to become stuck. There are a couple of other things that could be causing you a problem. The first is the gas cap and gas tank heating up and expanding. If you’re out mowing on a hot summer’s day and the lawn mower is getting hot, then it’s common for the plastic of the tank and cap to expand just enough to cause the cap to become stuck.
In this situation, I’d recommend leaving the mower in the shade switched off for a while, allowing it to cool down. You’ll find the plastics cool down and contract to make removing the cap much easier.
The last common reason gas caps get stuck is gas tanks pressuring. This could be caused by things like a lawn mower gas cap not venting correctly and even fuel boiling. These types of problems either cause a negative pressure/vacuum or positive pressure. Either way, the cap will be harder to remove. I’ve found that if you leave the lawn mower for a while, the pressure will become neutral, and the cap will come off without a problem.
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