Question moved from Cars and Trucks to model category.
I have two thoughts on this.
You either have water in the electrics from hosing the mud off, especially if you used a power washer.
Or
If mud and water got into the stator and coated the sensor for the CDI. It is magnetic, but in close proximity.
Basically strip and clean and spray WD40 in connectors.
Other ideas here. The ATV forums are a great resource.
https://www.google.com/search?q=2004+polaris+sportsman+600+backfiring
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Go back to basics. What EXACTLY does it do when you try to start it? Just spins it is often No spark. 'Coughs' and tries to start is possibly a fuel supply issue.
An engine needs 3 things to run. Air, Fuel, Spark. Did you check for spark on both cylinders?
Have you checked the air filter is clean. You will be surprised at how much a dirty one can affect an engine.
Have you checked for fuel supply at the cylinders. If you can get your head near the plug holes try this. Remove both spark plugs. Crank the engine for 2 seconds then remove the ignition key. Sniff the spark plug hole. Does it smell of fuel? Do the same for the other cylinder. Use the comment button below and I'll see if I can help you more.
Thanks for the apology. Cars and Trucks is the default category. I moved it to a better one.
Usually questions can be answered by Google. Generally if you have found an issue, then others will have as well and will have posted the solution. There are also pool companies that have forums where customers can post questions and someone at the store answers. Normally, I will find the answer for you but you didn't post the two most important words, 'make and model'.
Try Googling
make model getting stuck
and to see what makes it all work
make model manual
and make model parts schematic
There is a LOAD of information in this link and suggests you have to adjust the water flow and suction.
https://www.google.com/search?q=Pool+sweeper+gets+stuck
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Aww, dear old Larry Ng, AKA Gone forever
goneforever. Oct 22, 2022
NO gap means missing spec in manual or eyes looked at valve gaps and see none?
?????????????
It has HLA (Hydraulic Lifters) or solid tappets.
Get the service manual and see?
And some information from me! Larry was always economical with words, failing eyesight.
When it does not start spray come starter fluid into the throttle body/carb to see if it will run. If so, it is a fuel problem. Also check electrical connections for looseness.
Possible contamination of the fuel with water.
My guess is that Chinese carburetor is not jetted or set up right. It may not even be opening fully. Ask in the Polaris forums. Top speed should be 45 mph.
https://www.google.com/search?q=2001+Trailboss+325
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Question edited for clarity.
Question moved to a Polaris Snowmobile category.
Rattling is almost certainly the automatic clutch. Backfiring could be due to a few things, and is often lean mixture via the carb rather than rich mixture in the exhaust.
Check the plug electrode. Black means it rich, chalky white means it's lean. The correct colour is a straw hue and no fouling. Backfiring is a well known issue. Check timing as well.
https://www.google.com/search?q=1994+polaris+indy+sport+440+backfires+through+carb
Rattling can be other things as well as listed here
https://www.google.com/search?q=1994+polaris+indy+sport+440+rattles
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