Dirt in carburator from vent tubes?

[Lowedog]

I was just doing some jetting changes on my WR450 and when I took the lid off my carb I found the inside walls of the slide area caked with a light coating of dirt. There was even a little dirt in the bottom of the float bowl. It is really dry here now so the riding conditions are very dusty. The inside of the intake boot is very clean and the bike has been running good so I don't think I have a air leak somewhere. The only thing I can think of is that it is coming in through the vent tubes. Has anybody else had this happen? Hopefully I won't need a new top end because of this. ?

Lowedog

[yamahasocal450]

just because the airbox boot is clean doesnt mean dirt cant get into the carb... an improperly seated airfilter will allow dirt through.. whatabout the boot's seal... the boot to carburator gap is that sealed?... that maeks we wanna go check mine though ?

[Lowedog]

I'm sort of anal about things like the seal around air filter and the boot to carb and boot to intake so I really don't think that is where it came from. One of the vent tubes looks like it has dirt inside of it pretty far up it. I rerouted the top 2 hoses into the air box but I don't think that will make much differance since the inside of the air box gets pretty dirty also.

Lowedog

[gloft]

You can find small tube filters at some aquarium shops. Just insert them onto the ends of your hoses and oil the foam. I also saw a post where the guy used a film canister and routed hose into drilled end. He then put foam in the canister and used velcro to attach to the inside of his air box. Pretty cool.