hey try using some stuff called power tune it's made by mercury/mercruiser boat stuff we use it at work all the time I use it on all my stuff my toy my wife's infinity it eat's away at the black goo or carbon hasn't hurt any thing yet I even put it in my carb through the vent and let it sit over night and then you start it and let it warm up caution this stuff does smoke then rev the motor up and either close the choke or put your hand over the carb while reving the motor it causes high vacume in the carb and motor and will pull water and what other gunk is sitting it the bottom of the carb through the jet's water will not go through the jet's it's got to be pulled out this stuff work's good for 2 stroke's also try it beat's pulling you intake all apart.
