What to do with my 2 stroke engine tuning site?

So I am into dirt bikes and have a 2 stroke engine tuning site that I started for fun like 8 years ago. I contacted a bunch of folks years ago and got permission to put their tuning articles on my site. A couple of these articles are legends in themselves in the 2 stroke engine tuning world, and I get consistent traffic from them.

I have a Income Entourage squeeze page set up so you have to recommend the site on facebook to get access to the free articles which seems to be working ok. Thats only if they come in through the front door, so the article aren't really locked down, many just go straight into the articles from google search.

I want to monetize the site, but I am not sure what to sell on it. I tried some tools and things from Amazon but didn't get any sales. There isn't any clickbank products that fit.

I made a real half hearted attempt at adsense and averaged about $2.50 a month from it. According to adsense I get an average of 65 "page views" a day. I only have adsense on the home page, not in any of the articles themselves. So I was thinking of doing a full on adsense attack on the site but I don't know if that's enough traffic to bother with?

I have never done any SEO for this site, and at times I have just left it sit for several months without even looking at it. It's fairly ugly too lol

I have recently added a couple posts and it seems to be getting a little more than average traffic. The thing is, I can add good content to this site all day because it's what I am interested in and grew up around.

It's time to give it a tune up and monetize it.

Any ideas would be appreciated.