1980 185 missing gear

[jrb71]

recently bought 1980 185 runs great good overall. problem is there are only 4 gears . the owners manual says 5 where did 5th go.
i also need a headlight but don't know if it is a 6 or 12 volt:wondering

[Howdy]

What does the shifting do? Does it seem like it skips a gear? or does it simply not go into 5th gear? To best help figure out your problem here, we will need as much information as possible.

FYI, the 185's are 12 volt.
Howdy

[jrb71]

from neutral i can push the lever down into 1 2 3 4 then it just gets stiff and won't go down at all but i can shift up easily 4 3 2 1 n. it doesnt feel like it slips or misses any gears.