How to Troubleshoot Snowmobile Engines

A snowmobile engine, as with any other internal combustion engine, requires maintenance. One of the problems with snowmobiles, assuming you don’t live at either pole, is that use of snowmobiles tends to be cyclical. Snowmobiles don’t get used in the summer, which can lead to the engine fouling up with old gas. Troubleshooting a snowmobile engine, however, is easy.


1) Check the fuel tank to see if there’s gas in it if the engine turns over but won’t start. If it has gas left over from the previous season, discard the gas and replace it.

2) Check to make sure that the Off switch hasn’t been pushed in inadvertently if the engine won’t start.

3) Remove the shroud that covers the engine compartment then check the fuel line for any blockages. The fuel line runs from the tank to the engine. It’s usually clear so you can see if there’s a blockage. Again, this can be caused by improper storage. The fuel system should be drained fully after a season of use and before the summer storage.

4) Check the spark plugs when there are starting problems. Take a look at the coloration on the white porcelain insulator around the center electrode. Medium to light tan is normal for a medium duty snowmobile. Other colors can indicate problems with the engine. Very white can indicate air leaks.

5) Tighten the cylinder head nuts properly if the engine is having problems starting. The gasket may be worn or damaged. Take a look at it. If it is damaged, simply replace it. More serious damage could include a damaged piston and cylinder. Ask your snowmobile service agent to inspect them.

6) Make sure there’s plenty of coolant if the engine overheats or there’s a noticeable loss of power. The low coolant indicator lamp should illuminate.

7) Ask your snowmobile service agent to check that the carburetor settings are correct for the altitude at which you are operating the snowmobile. The clutch settings can also be adjusted for altitude.

Extra Tips:

*Add stabilizer to the fuel system if you don’t want to drain the system for the off season. Stabilizer is an additive poured into the fuel tank that helps preserve the gasoline from deteriorating over time. You can buy it at any auto parts store.

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