Jski550

A friend of mine and I own 2 2008 Polaris RMK 600s. We have been riding often at high altitude 10K + out here in Colorado. We have had trouble starting the sleds once they have been ridden and warmed up. As an example if the sled has been ran for 10 min plus and then shut down there is a 50/50 chance that the sled will start with 1 pull. Otherwise it is impossible to start until we have waited for about 15 minutes. The first few times this problem started I checked the basics, sparkplugs, sparks, etc. and everything seems fine. This is a fuel injected engine and I am normally familiar with carbs for I used to race snow cross where flooding can be an issue. Can a fuel injected engine flood? However this does not seem to be the case because the spark plugs often come out dry. Could this be a cooling issue? Temp seems fine and we are in deep pow. Seems like something electronic maybe. I knew I should have stuck with Ski DOO. Any ideas? Please help.