I have a stock 04 raptor, it has been completely trouble free after 1 year of hard riding. I have always had to add oil between oil changes, but it never fouled a plug, ran bad or smoked. Last night while riding out of the woods in the rain it began to blow blue smoke from the exhaust while riding easy ( smoked really bad for a few minutes ). You could see it easily from the headlights from the raptor riding behind me. I stopped and checked my oil level and no oil was on the dipstick. I had checked it before the ride and it was fine. I did notice something strange earlier in the ride, while setting and waiting on the other riders to take off after a short break I revved the motor slightly waiting to go and it stalled and made a slight clank type noise. That had never happened before. I dont think its a major engine problem - I dont know how the breather system works, but I am thinking I may have a problem with it. Any suggestions? I still have the stock air filter with I have heard is problem prone ( I have serviced it multiple times with no problems before). I have extended warranty, but would rather not take it to the dealer.