There should be almost no up and down movement.
If the pilot bushing in the crank is bad then you will get movement.
Bad front or rear bearings could also give you some movement.
Parts for these are on ebay all the time. If you have problems finding parts or need special advice PM me.
I know a number of tricks to make these 3 speeds work better.
You may want to check out my blog for one tip.
My blog link
