I just purchased a used 2014 Trail Tracker ex500 EFI with about 7000km on it. It starts up and runs fine as long as you are using the throttle but if you let off the throttle after about 5-10 seconds it will stall. Sounds like it just sputters out. The person I bought it from said it had been that way pretty much since he bought it but just couldn't be bothered to get it fixed since it started up and ran fine.

Just wondering if there is anything simple that I can do to try to fix/troubleshoot this? I will be taking it in to the local dealer to have regular maintenance and check up done since I have no previous experience with atv's but thought I would check here in case anyone might have run into this and it's something simple.

I also thought there was something wrong with reverse as well but it turns out I just wasn't stepping on the brake hard enough

Have you tried adjusting the idling speed?

In case anyone finds this thread, I wanted to come back and post about the fix for my issue. Long story very very short I ended up having some battery problems and found that my stator was bad  there was continuity to ground on all 3 leads. I ordered a new one and replaced it and now not only does the battery charge properly but the bike idles perfectly.

Good to know, I've got what I think is a bad Stator and am having issues with it staying running.  I assume the issue is with the EFI once the voltage it low enough the computer shuts down the fuel and spark.