When fitting Do not forget to put the small ( Easy to loose ) cone washer on the top of the yoke and on the bottom of the shim, I think you should only use the nylocks nut and leave the stn nut off as it do not leave any thread on the bolt, but look for your self.
As for the +2 shims I cannot see alot of use, may be 7-Kart could make some 0.5 shims for testing.
Good bit of kit, keep working on making the 7-Kart a quick kart and easy to work on and drive
cheers
trev
