Yuasa it is then ! Thanks that’s been so useful . I will buy a charger of eBay and see how it goes , there’s a motobatt 6 and 12 v on there for 19 quid so at least I can use it on other bikes . I also have a couple of BSA ‘s an M20 500 ( side valve ) what a character! , and a 650 Golden Flash ( looker ) , plus a 1978 550 / four . Talk about variety !! Poor old Honda will have to play second fiddle now but she’s nice around town unlike the ST .