I apologize in advance for my ignorance on this one, I'll try not to bore you with details and get to the point.... I currently have a 2009 YZ450 that I purchased as a leftover earlier this year to replace the 2008 YZ450 that I previously owned. The bike is pretty much stock and has approximately 30hrs on it (no aftermarket pipe, etc). I typically race a few harescrambles throughout the year and use the bike primarily for woods riding in SE North Carolina. I entered my first enduro this past weekend at the Sandlapper in South Carolina and had some issues with the bike bogging to a stall in corners after getting fairly hot through the tight stuff. During the third leg of the race (approx 25 miles from start) the engine completely died and I couldn't restart. I checked the gas and it appeared as though it was empty. The outside temperature was slightly over 80 degrees and the terrain was considerably tight compared to the typical harescrambles/GNCC's that I have raced in the past. After re-filling the gas, the bike started without hesitation and ran normally, so I decided to continue riding to see the rest of the course. Approximately 20mins after re-starting, the engine began displaying the same problem with bogging to a stall and was hot again. My questions are.... 1) I can't believe that I would have gone through all of my gas only 25 miles into the race. Could I have burned that much? Did I boil the gas out of vent from bike being hot? 2) Maybe the tank wasn't completely empty and bike was just overheated? I checked the gas but was pretty much in a state of delirium when doing so! 3) Could gas consumption and/or bogging be due to the engine running rich? 4) Solutions? I remember my 08 doing the exact same thing on a few occasions if it got really hot in very tight singletrack but never to the extent of this one. I think the difference with the 08 was that when it happened, the tight sections were followed by some open stuff that would effectively cool the bike back down. If it is simply an overheating issue (had coolant in bike)...Bigger radiators, engine ice, etc? Any suggestions would be greatly appreciated. Thanks.