dumb question. what is the fuel capacity for my '87 n/a?

 

Since you're a noob I'll go easy on you. Put on your flame suit, however. Before asking a question like that either do a search of check out the FAQ sticky at the beginning of this section of the forum. If you had you would have found this:

Where can I find links on specific 2nd Gen RX-7 information and models?
Searching this site is good. The search function can be found at the top right hand corner of the site. In addition these sites are recommended and can help with models and technical information:
https://www.rx7club.com/forum/showth...threadid=195286
http://2ndgenrx7.freeservers.com/page1.html
http://www.fc3s.org/
http://fc3spro.com/
http://www.mazdamark.com/FCseries4.htm
http://www.iluvmyrx7.com/
http://www.aaroncake.net/RX-7/
http://www.geocities.com/huguesdc1/
http://www.mazdatrix.com/faq.htm

Check out those links and you will find specs for all generations of the RX-7. Welcome to the forum.

 

16.6 U.S gallons. Found in the free, online Factory Service Manual. Fuel Section.