Guys, I have to say it is really too bad that your all having problems. Is it amazing that Cat brings out an absolute KILLER 700 twin motor with mega-horsepower and the whole issue is sidetracked by an air bubble in the coolant system. Talk about bad luck! You know the engineers tested the living hell out of that new design, as they new it was so different that it had to work the first time out for the consumer. Then after all of that, a stupid air bubble!!! I really feel for you guys. All the brands have had problems (Doo 800 twin and piston rings) but luckily (for Doo) it was rarer than the air bubble problems. The good news is that next year you know the air bubble situation will be remedied, and that motor will be the king of the trail for Arctic Cat. It really is a rocket! Good Luck with the F7s, no matter what, it really is an AWESOME sled. Excellent fit and finish with basically a 700 racing motor from the factory.