Hello,
I am having issues fitting a kick start return rubber to thd gearbox of my b31. The gearbox is a m series gearbox, i found the previous rubber had disintegrated inside the casing when i first opened the gearbox. I cannot get ths new rubber to fit into the casing wothout it working loose, does it go wide end or narrow end ibto thd grove? . I am also unable to see how go the the rubber to stay in place as i close up the casings. Sorry not used to British bikes!
If it's similar to my M21 box then it goes 'longways' into the casting - which should be tapered to match in both the inner and outer covers.
A goodly coating of oil - or spit! - will make it much easier to get it fully home.
Cheers,
Bernie
Had to trim mine down to match the taper in the case- a smear of washing up liquid helps to ease it into the slot