When your ATV isn’t working properly, especially when it sputters when you’re trying to accelerate, it can ruin your fun day out. Not only does something like this put a damper on your fun, but it can dig into your wallet as well. What could be the problem related to a sputtering ATV when accelerating?
The reason your ATV is sputtering when accelerating could be due to carburetor problems, spark plugs, vacuum tubes, dirty fuel, or other problems. Your ATV’s engine needs air, fuel, and sparks to keep it running correctly. When one or more of these are missing, it means the motor isn’t working properly and we need to diagnose the problem.
If you’re having these problems, all you want to do is get them fixed so you can get back onto the trail and have fun again. Without further delays, let’s take a closer look at the most common issues that could lead to a sputtering ATV when you’re accelerating, and the steps to take to get them repaired.
Here is Why Your ATV is Sputtering and How to Fix it
First, we need to narrow down what the problem is because it could be one of several different issues. Then we will discuss if it’s something that you can do at home, or if you’ll need professional help.
What is Throttle Bogging?
Throttle bogging is when you press down on the throttle, and instead of getting that jolt of power, the engine sounds like it’s going to die, and you go nowhere. It can be a frightening experience.
Bogging happens when the engine isn’t getting enough fuel, or not getting enough air. Combustion doesn’t happen properly and it can lead to the engine shutting off.
Throttle bogging can be caused by a clogged air or fuel filter, bad spark plugs, a dirty carburetor, or a foreign body in the fuel injector. Start by checking the filters and plugs, and if those aren’t the problem, clean the carburetor or injectors.
Now let’s check to see if you’re getting a spark.
The ignition system contains the ignition coil, spark plugs, and wires. All of these parts work in conjunction to provide the spark that ignites the fuel and air mixture in the engine cylinder. If any of these parts aren’t working properly either your ATV won’t start, or you’ll have performance issues such as sputtering instead of acceleration.
Possible Spark Plug Issues
Spark plugs can foul or get worn out by normal use, and should be replaced occasionally to keep your vehicles running properly. If these haven’t been replaced in quite some time, you should start by checking them.
Only pull one wire off at a time because they have a certain order they need to follow and it’s very easy to get them mixed up. Then you’ll have a timing issue to sort out on top of your current issue.
Inspect your spark plugs. Check for proper gapping, corrosion, damage, oil or fuel coating them, or simply worn out points. If you find one bad plug, go ahead and replace them all instead of just one, unless you have a single-cylinder ATV.
Spark plugs can be purchased for about $5 to $10 each. If all your spark plugs look good, move on to the plug wires.
Spark Plug Wires Aren’t Working
Look for any cracks in the wires and replace them if there is any visible damage. Also, check to make sure they are sitting snug at both points, and check for dirt or corrosion on these ends.
Any end corrosion or loose fitting plug wires need to be replaced. Plug wires can cost between $5 to $20 a piece or per set depending on performance and quality.
If your wires and plugs all look good, and you’re still not getting a good spark, the last thing to check is the ignition coil.
Ignition Coil Could be Off
The battery sends electrical power to the ignition coil, which then amps the current and sends it along to the spark plug wires and down into the plugs themselves. They spark and cause a tiny explosion in the chamber and your engine runs.
Over time, heat and use can wear out an ignition coil. It could also become physically damaged and no longer provide the necessary spark. If the ignition coil is the culprit, you should take it to a qualified ATV mechanic because they can still hold a strong electrical charge even after the engine has been turned off.
Next, let’s check the carburetor or other fuel supply issues.
Older ATVs often have carburetors, while others have fuel injectors. They both do the same thing, only fuel injectors are a bit less finicky than carburetors.
If your ATV has a carburetor and it’s sputtering, it probably has something to do with the problem. Either it’s not tuned properly, you have a fuel leak, or you have a vacuum problem somewhere.
Diagnosing and Fixing a Carburetor Gas Leak
A gas leak from your carburetor will be caused by a brittle or failed float bowl gasket. The tell-tale sign of a failed gasket is the smell of gas around the carburetor or you may see it leaking. The float bowl gasket sits just under the carburetor.
These are pretty easy to replace if you’re mechanically inclined, and they cost around $2 to $10. Most ATVs have a single carburetor, but if your model has more than one, go ahead and plan on replacing all the gaskets at the same time.
If the gaskets look good or you don’t smell fuel, maybe your carburetor needs a good tune-up.
Tune Your Carburetor
Tuning a carburetor is best left to the professionals. I wouldn’t tune a piano because it’s not something I’ve ever done, and would probably only make it worse. If you’ve never tuned a carb before, it’s best to pay a mechanic.
The service will only cost you between $50 to $100, and they might even clean it for you so you’ll end up with a machine that works better than before it started sputtering.
When the tune-up doesn’t fix the problem and the gaskets are still fresh, it could be a vacuum problem.
Possible Vacuum Leak
Your ATVs carburetor has several ports and hoses running to and fro. These are vacuum hoses that provide air to the carburetor and are options for customization. When these hoses become brittle, the clamps break off, or the hoses get clogged you can end up with sputtering.
These hoses and boots are easy to replace at home and don’t cost much, but they can sure make your ATV act like it’s got major problems. It will cost you less than $20 to replace the rubber boots or hoses.
Maybe your ATV isn’t bogging down but stalls out when you punch the accelerator. In that case, let’s find out what could cause it to stall.
Your ATV Stalls When You Give it Gas or Accelerate?
If you’ve come this far, we must not have fixed the problem. When your ATV starts fine and runs while idling, but then stalls out when you press the gas it could have something to do with the fuel and air mixture. Let’s check these issues.
Dirty or Old Gas in the Tank
Often, ATVs will sit for a time with old gas in them. Water can build up or rust can form inside the tank and it will need to be cleaned.
If you suspect bad fuel or a clog inside, you’ll need to take it off, properly dispose of the old gas and clean out the inside of the tank. Use a gas tank cleaning kit and follow the instructions. If your gas tank has rust on the outside or is flaking on the inside, you’ll need to replace it.
Once that is completed and the tank is completely dry, replace it and refuel it with new, clean gas.
Another area to check is the fuel pump and the mesh strainer.
A Dirty Fuel Pump Mesh Strainer
ATVs with fuel injection will have a fuel pump, and most times when these fail to perform, it’s because of a clogged mesh strainer. There are a lot of small, fragile parts here that need to be disassembled and put back together. The mesh strainer is best if it’s replaced, but if you don’t have an extra, you can clean it.
If you’re not very comfortable tackling this project, you should take your ATV to the shop.
The mesh strainer is the filter that prevents sediment from clogging the injectors. Once you get the fuel pump out, carefully remove the filter, and using a fuel-cleaning solvent spray the filter from the opposite side of the sediment. You don’t want to shoot debris into the filter.
Next, reassemble everything and refuel with clean gas. If this doesn’t fix the problem, you may have a low fuel pressure issue.
Low Fuel Pressure
When you turn on your ATV, listen to the fuel pump. You may be able to hear the pump kick on over the sound of the idling engine. What you’re wanting to hear is a low hum, if you don’t hear anything, you may want to check your fuel pump.
Most times when you have a problem with fuel pressure, the fuel pump is to blame. Replacing it should do the trick, though there could be a number of other issues that cause low fuel pressure.
You could have faulty sensors such as a MAP or TPS sensor, or it could be the ECU. You could go about replacing all of these one by one, or just take it to your ATV mechanic to have them diagnose and make the necessary repairs.
It only takes a few moments to check your ATV and keep it properly maintained. Here are the main things to check.
Make Sure to Give Your ATV the Proper Maintenance it Needs
Proper maintenance goes a long way to keeping your ATV working properly. This includes regular inspections to make sure nothing is broken or loose and replacing fluids and filters regularly.
Maintain and check all the fluids including coolant, brake fluid, and especially your oil. Be sure to maintain a regular oil change schedule. Gas may make the ATV go, but oil keeps it running.
Check the CV joints and boots to make sure nothing is loose or broken and make sure there are no loose bolts anywhere.
Be sure to add some fuel treatment, especially when you’re parking it for the season. Gas will break down over time which can clog filters and mess up the fuel pump. To save yourself an extra trip to the mechanic, add some fuel stabilizer if it’s going to sit for a while.
Ask a Professional
We hope this article has helped you diagnose and even fix your ATV sputtering problem. If you haven’t found the answer here, go ahead and talk to your mechanic. While we strive to find all the answers to your problems, talking directly to a professional is the next best thing.
An ATV that sputters when you’re trying to accelerate can be caused by any number of issues. The most common issues are bad spark plugs, wires, or a failing ignition coil.
When the ATV is getting a good spark, you should check that the ATV is getting fuel. Check the carburetor, fuel pump, and any filters, as when these clogs, they can cause sputtering.
We hope this article has helped you with your ATV issue, but if you still haven’t found the cure to your issue, we recommend you talk to a professional ATV mechanic. They can help you find the problem if you’ve exhausted all other avenues.
I’m William Guzenski, ASE certified master automobile technician & automotive expert. I love to attend race events and car shows throughout the country. I also loves to travel 40-foot motorhome, exploring abandoned mines and ghost towns. I’m currently building another car for Bonneville Salt Flats and will be campaigning a drag car at several events.