I bought my bike about 2 months ago.
Had 10 000 maintenance and had her to the woods 4-5 times since.
I clearly remember one of the guys took the air filter, used an air gun to clean the filter and put it back.
Anyway, I bought a twin-air filter and no-toil filter oil.
I had a chance to change the air filter tonight, but first I went downstairs to take off the old one.
As I opened the air filter cover, I got very mad, because there was dust in the clean side of the filter. The filter was completely black in color and full of dust.
So, I don't know what should I do right now, should I change the engine oil, because some dirt has clearly past the filter and got the the engine block. Or is there something I can do to prevent future damage ?