Try our new info resource - "Aladdin's Cave" (Main menu)Just added a separate link to Ash's Dropbox thread (shortcut)
I found on the 500 that no washer worked, perhaps i was just lucky
I know the one i did it on was a total mish mash of parts so i must have struck lucky for once.I wasnt using a taper "kit" but individual bearing from Hy-Level, top and bottom bought seperatelyand niether had washers.
On contrary I'm definitely fan of tapered one.I did that 3x already (CBF1000F, 750 K7, 550 K1).On 750 K7 and 550 K1 - under bottom one I used one of washers to keep OEM bottom bearing height. Upper, I had to grind upper cup that holds upper bearing. Yes there is appox 2mm gap as you noticed, Trig, but easy to fix, either rubber or stainless washer with right thickness.Handling is heavily improved! Especially later, no maintenance, much longer lifetime. On my CBF1000F it finally fixed many years present issue of hadlebar wobbling.
Contemporarily, many of us near him bought taper roller kits from Dave Degens at his Dresda shop over in Putney. He bought the standard size bearings and then had a machine shop grind one of them to make a straight swap from factory fit to comprise the kit. So that fits in with your experience here Trig. Must admit that I didn't pay much attention to exactly what he modded but fitted a fair few kits to friends bikes then. Always no adaption needed, and all installed as original kit. Seem to remember that the bearing id was missing from one of the faces, suggesting that they'd just been mounted of a mag base and skimmed with a linear surface grinder.Probably a little market here for correct set nowadays, that would fit properly as most seam to come up with the problem you observe.I've always felt as Erny does, they make a good mod for these bikes and are much move resilient than ball races.