I have just replaced the carb with a new one and I still cant get it to run. I cleaned the carb even though it was new. I have tried 3 different carbs. I replaced the coil and cleaned the fuel petcock. It will start and only run about 1/4 throttle and wants to start to die. If I kinda put my hand over the intake for a second I can get it to rev up completely but then it starts slowing down and dies. It wont idle. Im over this thing I have never saw anything like it. We have had it for probably 2 years and I have rode it once. I ended up using another carb off another 90 to get it to run. The new carb does the same as the other 2 that I have. I am starting to think a vacuum leak or something I have done a leak down test though.