My 1996 Suzuki GN125 runs fine as long as I don´t open the throttle all the way. I can feather the throttle and get it to run up to about 6500 rpm. When I open the throttle all the way, it just flattens out and the engine just bogs down. Ease off the throttle and it picks back up. I´ve had the carb off and cleaned everything twice, but it still does it. Any ideas?