How to Spot and Fix Snowmobile Engine Cylinder Problems


Riding a snowmobile is a thrill that never gets old. It’s incredibly fun and exciting, provided that everything is running properly. However, due to the seasonal nature of snowmobiles (riding only during winter), malfunctions are far more common than on regular vehicles, such as cars or motorcycles.

Riding in cold conditions, rough terrain, and sitting without ignition from winter to winter can cause many problems with your snowmobile. One of the most common issues is cylinder malfunctions. So, how can you tell if your snowmobile is running only on one cylinder?

If you feel a significant drop in performance combined with a slower-tacting sound, your snowmobile is probably running on only one cylinder. Other signs can be low RPM even in full-throttle, high gas consumption, oil leaking around the engine and crankcase, etc.

Many indicators can signalize a malfunction that causes your snowmobile to run on only one cylinder. If you experience issues like that, you should check it out and fix it because it can lead to huge malfunctions. The longer you wait, the more dangerous the malfunctions can become, and the more expensive the repairs will be.

How To Tell If Your Snowmobile Is Running On One Cylinder

As with any other vehicle, a single symptom you’re experiencing can mean many different things. For instance, gas leaking from the exhaust might mean the carburetor is clogged or damaged. It might also mean that air or fuel pipes are damaged, causing the engine to run rich. Perhaps the ignition and spark plugs are malfunctioning, etc. You can’t know until you check.

The same thing goes for malfunctioning cylinders. Many symptoms can indicate your snowmobile is running on one cylinder. Also, the same thing can be caused by many different issues, so I highly advise you to check everything when you see or feel a problem or, better yet, take your snowmobile to a professional to check and repair any malfunctions.

The number one indicator of your snowmobile running only on one cylinder is the sound. When everything is working properly, your vehicle will sound smooth when running. Also, you will feel a regular rhythm when riding. If you hear the sound of your engine has changed, or if the rhythm slowed down, that usually indicates that there’s a cylinder malfunction in question.

Another indicator you might get is oil dripping around the engine area. It happens when the oil injector is pumping too much oil into the cylinder, making it malfunction, or the cylinder doesn’t start, so the oil just drips out.

That’s yet another way to tell if your snowmobile is running on one cylinder. If you have trouble starting your vehicle, it usually indicates issues with your spark plugs. If you manage to turn the engine on, but it sounds funny, that tells you one of the spark plugs either doesn’t ignite at all, or the firing timing is off, causing the cylinder not to work.

What Can Cause a Snowmobile To Run On One Cylinder

One of the most common issues you can have on your snowmobile that causes it to run on one cylinder is a firing malfunction. It can be either the timing of the ignition or the spark plugs not firing at all. Try changing the spark plugs on your snowmobile to check if they were causing the problem. 

If the plugs were the problem, new spark plugs would make the engine run properly again. It will also solve oil and gas leaks around the engine and crankcase because those leaks tend to happen when a cylinder is not working, causing all the oil and gas entering it to leak out.

If the plugs weren’t the problem, it might be your fuel intake. You can check this by pouring a bit of fuel directly into the malfunctioning cylinder and trying to ignite it. If it starts running this way, it means you’re not getting enough fuel into it normally.

Another potential problem is snow buildup in the air filter.

Snow clogging up your air filter can interfere with the carburetors jetting. When this happens you might not be getting an adequate air-to-fuel ratio. Leading to one cylinder not running as efficiently. Abnormal jetting can also lead to dirty spark plugs which have a further negative impact on engine performance.

Next, you might have a worn-out piston ring because of which a cylinder isn’t working. If the ring is broken or worn out, it will allow gas and oil to leak, reduce compression in the cylinder, and make it malfunction.

Finally, the biggest problem you might have is with the head gasket. If there are only some screws, bolts, and vents loose, it’s an easy fix. But if it’s something more serious such as a break or a leak, you’re in for a very expensive repair.

More issues can cause your snowmobile to run on one cylinder, but you should get it fixed as soon as possible regardless of what the issue is. If you’re unsure how to find and fix the problem yourself, you should contact a professional. If you want to do it yourself, here’s how to fix it, depending on what the problem is.

How To Read Snowmobile Spark Plugs

If your considering it may be a spark plug problem. Learning how to read your spark plugs is very helpful and it can also help you diagnose other potential problems with your engine.

Reading your snowmobile spark plugs requires you to run the engine for a period of time. It also recommended to run it at WOT (wide open throttle) before checking them. As the spark plugs need heat and engine time to show their colors. Reading spark plugs is a bit of a learning curve.

Most snowmobile enthusiasts who read their spark plugs are trying to look for firing issues so they can better tune their engines. Again this is a fairly advanced skill that isn’t easy for beginners.

Color is one way to read spark plugs but there is more to reading your plugs than just color. Especially with 4 and 2 stroke engines. A flashlight and even magnify glass is often used to look for burn spots.

Check out this Spark Plug Color Chart to use as a guide.

How To Fix Your Snowmobile If It’s Running On One Cylinder

The first thing you should try is to clean all the fuel systems thoroughly. That includes fuel, oil, and air pipes, the carburetor, valves, vents, and eventually, the cylinders themself. If it doesn’t help, move forward with possible solutions. Clogs can cause a poor mixture of air and fuel, which can lead to cylinder malfunctions.

If the problem stems from bad spark plugs, changing them should immediately fix it. Sometimes, you just need to clean their heads from oil, carbon, and dirt residue. Perhaps they work properly, but they need adjustment in timing the ignition. Sometimes, bad timing causes the cylinder to fail to fire, so adjusting the timing might solve the issue quickly.

After that,  you should check the pressure in each cylinder. If there’s not enough pressure, it means there’s a leak somewhere. Most commonly, this is caused by worn-out or broken piston rings. Change them to see if it will solve your problem.

If the issue still isn’t resolved, you’ll have to find out if the gasket is the problem by tightening all the screws and vents. If there’s a break somewhere, you won’t be able to fix it yourself. It will be an expensive trip to the mechanics, but not as expensive as changing the entire engine if you wait for too long.

Your safest bet is always a professional mechanic, but solving the issues noted in this article will do the trick most of the time.

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