Yamaha YFZ450 3

I just bought a 2006 left over yfz450 about a month ago i must say its 1 sick machine seriously. But i have a problem that happened about yesterday i was riding and i was fallowing about 20 people and just cruising in 5th hear for about 5 minutes and it wanted to shut down it kept bogging out and wanting to shut off and i went to stop. It wont let me take off right i have to keep it in a really high Rpm and beet the hell out of it to get back to my truck it still took about a half hour and yet ll it wanted to do and it did was bog out and cut off on me its kinda hard to explain but does anyone have any suggestions about to what it is?