I helped my brother assemble his GRUBEE SkyHawk GT5 66cc/80cc (Black Finish) kit, got it running the first start. there is some bogging at 1/2 to 2/3 throttle. 3rd trip I rode it for about an hour, parked it for a few hours then went for another ride. I started tinkering with the idle speed screw and the air/fuel mixture screw. Immediately started bogging even worse, so i tried adjusting them back to there normal position, didn't work. The motor will start now, but giving it any gas bogs it to the point of dieing, and as soon as i disengage the clutch the motor immediately dies. I think it has something to do with the carb but i'm not sure. Saw a video on youtube where the main jet? had completely come unscrewed, maybe that's a start. I will take it apart tomorrow. If anyone could give some incite it would be greatly appreciated.