The Hiflofiltro HF204 'premium' oil filter, available for about $10, fits perfectly. It is an exact match to the Honda filter.
Sorry for reviving an old thread.
I've been using the K&N 204 filters on my NT, strictly for the 17mm nut on the end of the filter.
With that nut and having a ratcheting 17mm box-end wrench; oil changes are much easier.
A few years ago, I bought a case (10 ? 12 ? ) of the K&N 204 filters. For a cost of $7 per filter.
After my last oil change just a few days ago. I am now down to one K&N 204 oil filter.
So I went to the website of where I bought the filters last time.
And to my surprise; they had more than doubled in price. They are now $18 per filter !
I did much searching online. But $18 per filter appears to be the only available price.
So just to to have more than only one spare oil filter. I went to local Autozone and bought two they had in stock; for that $18 price.
With your post and doing some research online. I've learned that HiFlo also makes an NT compatible filter with a 17mm nut on it's end.
AND as you stated; is available online for $9.99 per filter.
That filter is:
HF204RC.
Would this be the HF204 you are using ?
If yes; would you (or anyone else) be in any position to compare it to the K&N 204 filter ?
Thanks;
--ET