I am having troubles with the shifter in my 88 900 turbo. It would only go into a couple gears (3 & 4) and was very sloppy. I pulled the housing out and replaced the plastic bushing and rubber grommet where the shift rod enters the front of the housing. I put it back together in 3rd gear with a drill bit in the locating hole to line it up. I am still having issues, it is very hard to get into 1/2 and 5/R and usually I can't get them at all.

Is there another adjustment I am missing? My reverse lockout is not working, does the shaft length on the end still need to be adjusted?

The "reverse lockout pin" does more than make the reverse lockout work. It guides the shifter along the path inside the plastic plate on the underside of the shifter housing. You probably need to adjust that first. Fix that and then post an update. It could be other things but I'd start there.

its also possible that your reverse logout mechanism has fallen apart or gotten some piece of junk in it that is preventing it from working properly.

After discussion on the 900 Facebook group it looks like my shifter has been "modified" at some point. I'm not sure what the extra piece screwed on the end is but I'm going to try a different shaft assembly.

A replacement shift selector did cure the issues, it now shifts smoothly into every gear (except second but I knew that was crunchy).