NAPA Gold, or another higher quality filter. Old post, I know. I have read that the K&N air filters let too much dust/dirt pass through. I like the concept of the K&N air filter, but have never bought one because of this. And i did a lot of research on it. That was about 13 years ago. Has anything changed since then?
I run K&N filters on my twin Weber DCOE 45 carbs. Each year I clean the filters with K&N Filter Cleaner and re-oil them with K&N Filter Oil and I have never had any dirt buildup in the carbs or on the throttle plates. The filters have been on the carbs since 1990.