01 polaris question air/fuel

[NoLimitzInd]

hey guys, I got a quick question. My boy has a 01 polaris 90. It seems to cut out after riding it for about a hour. I cleaned the filter, put a new fuel filter in it. still seems like it is cutting out alittle still, hard to say for sure since I just rode it up the street last night. Well I pulled the plug and took it in to get a new one. The guy said it looks like it is running a little rich. Could it be that I have it turned down? I have the throttle limiter turned down alot really. It is his first quad. The guy at the shop said that could be it for sure. Just wanted to ask some of you guys here too. Thanks