I got a Polaris 500 mag why is it not giving me all the power and back fires when I push the throttle all the way and it only does it after I run it for 20 min or so???

Check air filter make sure its clean, fuel lines are clear and filter clean or new, is the gas old? Carb or injector? if carb possible needs cleaning. could also be fowled plug

clean out the carb first

Yes you do or just go to the store that you bought it or return it to the person that you bought it from. Thanks for my option

Does the cooling fan ever run when the engine is hot? If not, you may have a problem with the fan thermostat.

For the record, spray carburetor cleaner does no good if it's sprayed on the outside of the carburetor with the engine running. That's not what it's for.

sounds like the coil is weak or the electronic spark box is goin fuel filter been changed ?right gap on the Plugs? need more imfo on it to do more thks

follow ur throttle cable down to cars there should be a plastic screw close to cable to adjust idea but with polaris that screw can be hard to find with all the plasticc they put in way but if u can see carbs easy enough u will see the idle screw

May be fouled plugs. If not check vent hose on carb.

stator pickup or stator coil

If you are certain the spark plug(s) is in good condition and correctly gapped, and the magneto is working normally, then you may have a fuel system problem. A quick diagnosis of fuel system issues is to spray a shot of starter fluid or WD-40 into the intake through the throttle body. If the engine fires for a bit then quits, it's a fuel system issue. Small engines do not do well with old ethanol-containing fuel. If it's turned yellow, drain it out and replace it, and remove any in the carburetor float bowl also.

Air leaks in the carburetor or intake manifold gasket may also cause hard starting. A sticky carburetor float or float valve is another possibility, especially if the engine was sitting for a long time with ethanol fuel drying out in the float bowl. A dirty air filter will also cause starting issues.