Unless you're browsing /pol/, I wouldn't consider any of the boards really dedicated to racism. There's unfortunately a lot of random racism throughout though. Again, unless you're finding the comments agreeable then it's not an issue.
I mean, if you sympathise or even empathise with their viewpoint, then yes, you are a racist. If you look out of sheer curiosity but categorically despise their views, then I don't think you're racist. If you visited the forum, either consciously or subconsciously looking for like-minded people or people who have similar views to you, then you're a racist.