well I had it off today (ooh vicar)
took all the plates off and put them back in. the new springs were about 5mm longer and da daaa, it all fits in nice and tight.
probably it was the springs not putting enough tension on the plates, even though it wasn't slipping before hand!
managed to set the float heights and a quick test on the bike and it purrs on tick-over, no nasty rattly noises and revs cleanly too.
now i have to get new fuel tap rubber and gasket as it pisses out of there, being removed for epoxy tank lining.
nearing the end of the tunnel now
thanks guys for your input as it does help putting things into perspective.
new order for bits to yamaha and that should be it