linkage

Hey all, just joined this group. Recently bought my first bike, a 1974 CB450 K7. I'm going through it and doing some maintenance, been working on my own cars for awhile but honestly know nothing about motorcycles. Dunno if specific trouble shooting is welcome here but thought I'd give it a shot...

So today i decided to take out my '71 CB175. I take it down the alley and out of nowhere while shifting up into 2nd, the shift lever just stays there, it doesn't return to the center position. Same for when i shifted down to 1st, it just stayed in the down position, i tried getting it into...