Hi all,
I have a 2001 Sportsman 500 HO.
Only about 125 miles on it. I only use it a few hours a year.
It starts perfectly, idles and runs great. But after 5 minutes it shuts down (stalls). When I try to immediately restarted it kicks back and backfires from the exhaust. If I wait 5 minutes it starts right up and does it all over again. I pulled the carburetor and rebuilt it even though it looked spotless. It still does the exact same thing. When it's running it performs as it should until it stalls.
It doesn't sputter and stall like its running out of fuel. It's more as if the key was turned off.
l'm not 100% sure on this, but it seems like the hotter the outside temp is, the longer I have to wait to restart it successfully.

Thanks,
Ringwood

 

Check for spark when this happens. If it has spark,pull the recoil cover and check for dirt/mud around pick up coil and flywheel. Plus white to white/red pick up coil wires should ohm out around 97 ohms. If it doesn't have spark when it dies,could be a stator shorting out.

 

See if its a gas vent problem. Run the ATV with the gas cap off and see is it still does it.

I had that on my Big Bear the gas tank venting was screwed and the ATV would only run for a short while and stall but with the gas cap off it by passed the tank venting and could run all day.
Turned out the gas cap vent tube was plugged.

 

Thanks for the replies. I pulled the starter cover off. I was going to see if the pulser coils needed adjusting but it looked non-adjustable. The screw holes that hold it down as well as the metal strap keeps it in a fixed position.

I ran it again at idle and it didn't stall. I took it for a 5 minute ride and it bogged down at 1/3 throttle. Definitely felt like carb. I pulled it again, and on this cleaning I threw it in the ultrasonic cleaner. The only thing I noticed was that the needle jet wasn't aligned correctly. The pin in the carb body backed out. I fixed that and reassembled.
When I restarted, it idled great without stalling. I let it idle for about a half an hour.
I took it for a short run through the woods. Ran strong without any problems.

I left it idling in neutral and walked away. Five minutes later it stalled. I restarted it ok. It's been running great ever since. I've let it idle for a while, taking it for a ride, letting it idle again starting and stopping it. It hasn't given me any problems for 2 days and it runs great. Still scratching my head a bit but I'm not having any issues with it now.

 

Forgot to mention that I did check the fuel vent hose. It was clear.
Thanks.

 

Small things over looked can be a pain at times. Here's something you can look over. It's the pdf fuel section from the service manual on the vm and bst 34/40 carbs.https://www.google.com/url?sa=t&rct=...,d.aWw&cad=rja Plus the pick up coil is "technically" not adjustable,but they can get knocked back when pull start rope assemblies break or parts come loose.On this you can gently tap the bracket inward decreasing the distance from the face of the coil to the flywheel magnetic strip.Manual shows distance should be between .016-.040.