sticking throttle

[coreo5]

My 250 Honda ex has a sticking throttle. The problem is the carberator slide it gets sticky stuff on it after running for a few minuetes . I have put fresh fuel in it and cleaned the air cleaner, checked valves but were both perfect. and im not running rich, I think the sticky stuff is coming backwards from the head to get on the slide!But I dont know what would cause this or how to prevent it.any ideas or suggestions would be appreciated.

Thanks

[313racing]

check your throttle line it might begetting caught up on something
did u recently take off your carb or work on it???
o and by the way welcome to the site!!!

[coreo5]

thanks for the welcome....but the throttle cable isnt getting caught on anything....i can ride it for a few minutes before the throttle starts to stick.....my 250 is backfiring and is blowing back air and other materials through the carb and thats what making the slide in the carb stick.....but i do not kno why it is backfiring. everything seems to be right....im about to go take it to my local honda shop if yall cant help me here