Long time no post but I could not resist commenting on this one I removed the original muffler on my 76 F1 just after I bought it in 76 as it was too quiet, ugly and had no ground clearance, I pored two stroke oil into it to stop it rusting and it now lives in the loft I replaced it with a Dunstall one which I still have but it is far too noisy for me now.
Cheers
Den