I’m having some trouble with my 2005 Polaris Sportsman 800 EFI. The engine cranks just fine, but it won’t start up. It seems like it’s not firing, even though it’s turning over. I’ve checked the basics but I’m stumped on what could be causing it. Has anyone else experienced this issue or have any suggestions on what might be going wrong? I could really use some advice.
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It could be a few things, but based on what you’ve described, it sounds like you might have a problem with the spark. If the engine is turning over but not starting, one common issue is a failure in the ignition system. Check the spark plugs for fouling and ensure they are in good condition. Also, inspect other ignition components to make sure there’s no failure there. In some cases, low compression or high cylinder leakage could also prevent the engine from starting properly, but that’s less common.
Thank you all for your suggestions! After going through the advice on the forum, I decided to check the spark plugs. When I pulled them out, they were covered in black, sooty carbon deposits and seemed a bit wet, which pointed to fuel flooding.
It became clear that the plugs were fouled, likely from a rich fuel mixture or incomplete combustion. I swapped out the old plugs for new ones, cleaned the ignition coil terminals, and checked the spark plug wires.
With the new plugs installed, the engine started right up and ran smoothly. It turns out the fouling was the main issue, and thanks to the forum’s advice, I was able to get my Sportsman 800 running perfectly again.
I really appreciate the help from everyone—it made a huge difference in getting my ATV back in great shape!
One possibility is that your fuel tank vent might be plugged or pinched. If the tank cannot vent properly, it could create a vacuum and prevent fuel from reaching the engine. Also, consider whether the engine might be flooded. If you’ve been cranking it a lot, it’s possible too much fuel has flooded the engine, which can prevent it from starting. You might want to let it sit for a while and then try starting it again. Additionally, check the spark plugs to make sure they’re not fouled. If there’s no spark, the engine won’t fire up.
It sounds like you might be dealing with a fuel issue. Since your engine cranks but won’t fire up, it could be that you’re not getting fuel to the engine. First thing to check would be the fuel level and ensure that there is indeed fuel in the tank. If that’s fine, you might want to inspect the fuel line and filter for any dirt or debris that could be blocking the flow. Sometimes the fuel pump can become inoperative or restricted, so checking its operation is also a good idea. Additionally, make sure the fuel valve is working properly and not clogged.
Good luck, and let us know what you find!