Recommended 912ULS Air Filter?

Thanks... I've looked at the specs, too...  To complicate things, there is an angle (20 degrees, I think) on the flange.  It's a tight fit in the RANS design.

Making an adapter is probably the easiest way to go.  

K&N Part # SN-2540 & 2530

https://www.knfilters.com/search/universal/round-tapered-universal-air-filter/viewall?srsltid=AfmBOopEeiJIaLpETf0zw2iQxkKSJRxbKKABacieLHSUZFQJGkWVfz2D

I did find the SN-2510, SN-2520, and SN-2530.  It looks like they have the same specs except for the height (one is 4"", one is 5", and the other is 6").  The 6" is too big for sure.  Maybe the 4" or 5" would fit.  They all have the same flange ID as the discontinued SN-2540.  Which brings up another question: I don't see any specs about airflow on any of the K&N filters.  It seems like it would be a mistake to just choose a filter based on physical parameters without considering the flow rates? 

Hi Michael,

In the past, I have tried to get airflow specifications from K&N - no luck!

Without airflow, you will just have to go on the dimensions and make assumptions about filter area.

I don't think you will have a problem. In my case, I have a spare filter ready to install, at every 50 hrs - so far so good!.😈