We have a 99 500man that just wont keep running. Have changed filters and checked vents( it even does it with the fuel cap off) Whats happening is the bike is sometimes hard to start( i say sometimes because sometimes it fires right up ) and once started will periodically stall out while idling.We have a small sprayer mounted on the rear racks and im wondering if the sprayer pump is somehow draining down the electrical system? Any thoughts? Bad battery?? fuel? charging system??

 

If the starter turns, the battery is fine.
If it stalls in the idling process, ever thought of adjusting the idle adjustment?
Try that out

 

When it starts hard is the starter slugish? Or is it the same when it starts good.

 

You might.. Eliminate the sprayer from the circuit first!

Disconnect the sprayer and retest system before making any assumptions.

 

maybe your fuel tank has some dirt in it and it blocking the fuel line offand only letting the gas dribble through to the engine.just a thought.

 

Check for fuel contamination ( water ), Water can do just that, drain the tank or fill with new gas and add some dry gas most gas stations have the stuff $1.99 Good Luck!
I had this happen to my ride on lawn mower the dry gas did the trick

 

Have already tried all the above suggestions LOL.... We run ethanol blended gas in the 500 so I dont think it is water contamination, although it did cross my mind. As for the hard starting sometimes it just wont turn over, press the starter button and I just get a clicking sound, then 5 seconds later Ill hit the button and it turns over fine. Once its running it runs great until we let it idle down. SOMETIMES ( not all , thats whats puzzling)it will stall after 10-15 seconds of idling, the next time it runs for 15 minutes with no problems. It does the same thing with or without the sprayer connected but for some reason i think the problem is electrical related. Is it possible for the sprayer to have drawn down the batteries so far that its somehow affecting the ignition circuit?? Bad coil maybe??

 

I had the same type of issue on my 98. Take carb off and clean it completly, with air and cleaner. Esp pilot circut. Then check the float, mine was out out big time and after the complete carb cleaning, and float adjust my issue went away.

 

dont ask me to explain but have you checked the needle/seat in the carb and to a lesser extent the float height?

 

Do you shut your fuel valve off after ridding?

I started having a problem like you describe and found that fuel was filling up my cylinder. Sometimes I was able to get it started with the electric start but once it was so full I could not even use the pull start. Had to take the plug out and push the fuel out. After cleaning the carb and replacing the needle and seat. I have no problems.