I have a 1994 300ex and am having carb troubles with it. It runs fine until I either pop a wheelie or go up a steep hill, then it starts to act like its running out of gas. It will run fine again (until I go up another hill) if you gas it till it revs way up. The carb has been cleaned several times and has no dirt in it. It runs fine no matter how hard you gas it as long as its on flat ground, and I am pretty sure its not flooding since it doesn't smoke while its running bad. Also, where or how can you put an in-line fuel filter on a 300ex?

 

i had a similar prob with my old 300ex it may be the floats i know that after i rolled mine the floats got stuck you can check to see if there stuck of you lift the front end up a couple of feet i recomend parking it on a steep hill if it starts leaking gass out the bottom in a steady stream its the floats and the leaking could lead to a lack of fuel in the engine