How many bikes approximately were made with the big breather bump in the top and how many with the earlier smaller bump?
OK, I'll bite. This'll start another bunfight for sure:- 1992 Super sports & SL (variants 350cc = 751, 400cc = 300, 750cc = 2973 900SL = 1317 & 900ss = 3500) small bump tank was first in 1992, changed in 1993 to larger box type, 600ss appeared in 1994, total production figures rounded minus the above mentioned, I've had vino, so all of this could be total bollox of course:-( (approximate number of box vent tanks per model) 900ss/sl/fe = 20,000 600ss = 4,350 750ss = 10,000 400ss = 2500 light blue touch paper and retire immediately, if not sooner.
I think you are out by one year. The 91 bikes had the round bump, along with the 92 mk1 SL. The rectangular bup came in on 92 bikes, although this being Ducati I would not be surprised if a few 92 bikes had that tank too.
thanks, I realised my 1991 omission too late, my apologies, 1992 ss/sl had small bump tanks too. EDIT: 1991 ss tanks approx. 6,500 production figures lifted from this book, again.
I have two 'small breather' tanks of similar vintage. One 1991, the other 1992. While i realize there are a number of variables at play, I have this information to offer concerning the cause of rust.... The 1991 tank that was left in a shed full of fuel for 13.5 years - NO internal rust, but some surface rust on the under side. The 1992 tank was used continuously on a relatively high millage bike. It was totally rusted internally, and leaking - NO surface rust underneath.
