Wow, the plot thickens........that is a good link, thanks goudrons, I have some of the spec listed on the link but not all of it. I have a 37 & 38 s idle but only up to a 96.02 main. my slide matches but my needle and floats dont!...............the whole experience with the keihin over the past couple of years has scarred me, so I may wait a bit and see if anybody who has one fitted on a 315 and fully dialled in shares there knowledge on here with me and everyone else, luckily I have (learnt) that patience with stuff like this can pay off.