A hidden problem with a stiff throttle, is the gears in the throttle housing .
They are made from cheap ' pot metal ', they wear and bind up the throttle .
The throttle and choke splitters are not that big of an issue .
The problem with from what I've seen, the ' 82 and later bikes have problems with removing the cables from the plastic plug inside the splitter .
Had me puzzled for a bit !!!
Solution, open up the slots on the plastic plug at the top of the grooves for the cables, so the cables can come out the side of the side and not the top .
Once you do it a few times, it's only a two minute job .
I used to lube the cables every year, but when I got my oilhead 14 years ago, I decided not to lube them and see what happens, 14 years and 60,000 miles and still no issues .