2012 wr Dirt getting past air filter

I have noticed a thin layer of fine dust on the inside of the intake boot just past air filter. I can't figure out where this is coming from. I have checked everything, no holes or cracks in boot, clamps are tight and properly aligned. Air filter is new with proper oiling and lined up correctly. Only thing I have not checked is the big clamp inside the air box. It seems tight by hand but I can't figure out how to get to the bolt to actually check tightness. Any thoughts or ideas?

Grease the perimeter of the filter.

Are you soaking the air filter with oil then wringing out the excess?

Yes, i am soaking and squeezing excess. However I do not grease the perimeter. I assumed by soaking and squeezing there is enough oil on perimeter for proper sealing. Plus it is less mess to clean up each time. I will try the greasing and see if it stops.

If it was a carb'd bike, I'd say your vent lines are sucking in the dirty air from under your bike....

+1 on grease the perimeter and make sure the air filter is hand-pressed all the way around to make a nice union between filter and where it makes contact with box.

Cool, thanks for the reply. I will grease and keep everyone informed after next couple rides.

Talked to a very competent Yamaha mechanic today about my issue. He told me that the union between the rubber intake boot and the hard plastic it is sealed to (by the big clamp) on some bikes allows dirt to enter. This rings a bell with me, as I seem to remember reading this very issue happening on older yz bikes. Solution is to take apart completely and seal with silicone at this union. I do agree with this because when I am looking at the dirt inside air box it seems to really be concentrated at that union.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!


Register a new account

Sign in

Already have an account? Sign in here.


Sign In Now