2004 500HO won't idle after normal warm-up time, have to keep giving it throttle to keep it running. After riding for 5-10 minutes it will idle on its own, but rpm will vary from 900-1150 (normal idle is about 1250). Also seems to sputter out the exhaust (almost like subtle backfiring) when I let off the throttle quickly, otherwise it runs great except at idle. I thought it was water in the gas but that wasn't it. Plug & fuel filter have been changed, air filter is clean. Any other suggestions? I guess cleaning the carb would be next.

 

chances are if it starightens it self out some what after warming up then i would guess the carb wouldn't be dirty as the issues shouldn't go away just by warming it up.(imo) by any chance is thier any kind of exhaust or air leak of some kind causing the changes in the idle? just a thought.

 

I've checked for air leaks & the only thing I've found is some surface cracks on the rubber piece that the carb attaches to, but they don't look nearly deep enough to leak. Haven't looked at the exhaust, but that would make sense. I think it's one piece right back to the silencer so there's not too many places it could leak. Must be a gasket where the silencer meets the pipe though so maybe that's it. I'll give it a look. Thanks.

 

Try spraying some carb cleaner on the carb boot when it is running. If it runs faster as a result, those cracks are all the way through and it is sucking air and time to change the boot. Might be a good time anyway for if it leans out too much the result is a scored piston.

 

Need to drill a hole in the brass cap that is covering the air-fuel screw, then screw a sheet metal screw in it and remove the brass cap so you can set the screw at 2.5turns out, Polaris put out a service bulliten on this some years back, I have done several and found the screw anywhere from 3 turns out to all the way shut. The brass cap and screw are on the bottom of carb

 

You might try adjusting the throttle cable, after 6 years it might be stretched just enough to not idle when cold. Corrected the same type of problem on 1 of my 02 500s.

 

Well I took the exhaust apart and one of the gaskets is very worn & shiny, looks like its been spinning around in there for quite some time. I'm hoping this is the problem, I'll pick up a new one tomorrow and see if that does the trick.

 

Whether that's the problem or not, I would do what a couple others have suggested. Make SURE your throttle cable slack is adjusted properly. Then, get that brass plug out of the carb so you can adjust the idle speed fuel/air flow mixture. The manufacturers have to set them lean to meet government regulations. If you are running gas with Ethanol in it, it will only run leaner... that's why you need to be able to adjust that mixture.

 

Throttle cable adjustment is good. Air-fuel screw was 1 3/4 turns out so I turned it to 2 1/2 out.

 

let us know what you find that fixes it.