I've got a couple of flywheels at home which i've actually measured.
I have one that I believe is from a smallport redtop (AE92)
6.8kg
And a blacktop flywheel (AE111)
6.05kg
http://www.club4ag.com/faq%20and%20tech ... lysis.html
Check that link. Somewhere down the page there is a listing of flywheels. The results from there match what I measured so it must be good and accurate.