2006 YZ450F. The problem I keep having is that I am getting a pretty good deal of fine dust in my carb on the slide and in the slide chamber as you can see in the pics. It's done this since I got the bike and i can't seem to find the source of the problem. It's been REALLY dusty the last two times I've been out but I never had this problem on my other bike......at all. Before I went out this last time I took the airbox apart and siliconed everything to make sure nothing was leaking there and judging by the cleanliness of the airbox after this ride, it isn't leaking. Also, if it were leaking I would think the area around the air jets would have this orange dust on it which it doesn't. So that leaves a leak in the carb somewhere. The first time I saw this mess I replaced the top oring on the slide cover. That didn't work. Now I'm just stumped. Could the hot start be leaking somewhere or are there any other areas of the airbox or carb that I need to check that I don't know about? Grrrrrrrrr. This is not making me happy.:smirk: Oh yeah, I completely cleaned the carb before going out this last time.