I've got my 1992 YS1 apart right now, and am debating whether to re-use some bearings or to buy new ones. I am replacing the diff carrier bearings and both bearings at the shaft bases, but I might re-use the 2 at the tops of the shafts.
Question is, how can you tell if they are still ok? The top mainshaft bearing (the 3-4 inch diameter ball bearing) has some play up and down - the inner ring can move slightly vertically in relation to the race. There is a slight wear ring under the ball groove (more like a polished area), probably caused by this. Is this normal? How tight is a new one supposed to be?
Similar case with the uppermost countershaft bearing - slight up/down movement of the inner ring in relation to the race. The inner ring also moves back and forth slightly.
Any ideas? These 2 bearings are around $70, and I have already dropped $200 on assorted trans parts...

 

Bump for bearings

 

The two input shaft bearings are the first to go, especially the one closer to first gear. I ALWAYS replace those when I have the tranny open.

 

The input shaft bearing close to 1st was shot - pieces were on the magnet. The big one at the other end should probably be replaced too, you say? What do you think about the countershaft? Should I replace the 5th gear side bearing? Can I get away with just replacing the top bearing (ball bearing), or should I replace that and the roller bearing below it (with removeable race)?