You need to remove 32 bolts for the tupperware and tank, 4 nuts for the coils, 4 spark plugs, 6 valve cover bolts and the TDC access port. Fingers can get blistered even before you get to the valve adjusters.
More seriously, after 4 years and 20000 km, only one exhaust valve was 0.001" too tight. And many thanks to your favourite deity, the '86 cams are not pitting.
Well, now that you have 91,000 km on it, I would hope the valves settled in and stabalized....
20,000 km is the normal service interval in the book for new bikes, after you get 50 k miles on them... you can start stretching that interval based on wear patterns.... the last couple years of ownership on my '86 I checked mine at 25k mile intervals, and never found them worse than .001 " out... it had 138k+ miles on it, and ran smooooooth...