ok, I cam across this old 1985 kdx 200 (2 stroke). Basically what is happening is when I go to start it, it is very hard to start unless I push/tow start it. it also back fires some. when it does finally start sometimes it revs up pretty high and when I actually start riding when I start shifting into higher gears it starts to bog down and losses probably 1/2 of its power. I have pulled the carb off and cleaned it throughly twice. Somebody told me that the new sparkplug i puit in it is probably not gapped right and I need to play around with my idle screw but i thought I would ask people with more knowledge in this field. if anyone knows what the problem is or knows what i can do to fix it any comments would be greatly appreciated.