FD speedometer moves slow
 

So I just picked up a 1992 FD (JDM) a few days ago and for the most part, everything works well. However, I have noticed that my speedometer moves very slow. For example, if I accelerate from 0 to 60, by the time I reach 60, the needle will only be at about 40 and still slowly be climbing its way to 60. It does the same thing when slowing down. I tried searching, but only found one other thread with the same issue and no answer...Any ideas for me to try?

Anyone???

Might be gummed up my tach does the same thing. Took mine apart and put one drop of light oil on the shaft and it sped it up. But I actually think that was a bad idea because it gummed up more after a bit. The oil probably attracted more dust or dried up, probably need to clean it out completely but don't know what with? Maybe a can of electronics cleaner and compressed air ?