I purchased a 400 auto in May of this year, I love it, what I don't love is the fact it will not idle after it has run for about 10 minutes. It acts like someone just turned a fuel valve to off, the engine speed just keeps getting slower and slower until it quits. At first it would only do it once a day, but now it won't idle at all when it's hot, you let off the throttle, it quits. Dealer put a new carb on it, even ran it with a portable fuel tank to eliminate the fuel in the unit's tank as the problem, still does it. I am thinking it might be electrical, any thoughts?

 

Does it restart after it quits? OR is it hard to start after it quits?

I had an old Suzuki quadrunner that had a problem with the CDI. When it had ran for a while it did just as you describbed except it would not restart or even fire until it had sat and cooled off for about 2-3hrs. Your dealer should be able to test the CDI to rule it out.

Hard starting can also be caused by your valves being out of adjustment. So check your valve adjustments.

Also, I believe the 2007 models have an electric choke but I am not positive on that? If it does you may want to check its operation and your plug color.

SJ

 

I just got a new '08 500 auto and have what sounds like exact same problem. I might try increasing idle speed although a previous post suggested that may make gear selection tougher. I'm also thinking it might have something to do with cold weather (7 deg F). Is weather cold where you are?

 

Cold weather would effect it for sure, but a choke that is not operating correctly will probably do this as well. I am pretty sure the newer models have an electic choke. My manual choke ATV's will do this if I forget and leave the choke on. But, it also makes it run so rich that the plug gets all carboned up and is not the tan color it normally is.

SJ