I started having difficulty shifting (would go up or down only one gear from current position, or would not shift at all), so I took off the external gearshift mechanism cover to see what was going on.

When I took the cover off, I noticed that the teeth on the sector gear on the gear shift shaft were barely engaged with the teeth on the cam drive gear (rather than engaging on the same plane, the sector gear was somewhat outboard of the cam drive gear).  

Next, I began disassembling the external gearshift mechanism.  As I pulled the gearshift shaft out, the return spring that came out with it was cockeyed and one of it's arms was not properly engaged with the catch on the back of the sector gear.

I was stumped by the screws holding on the cam guide (why the hell are screws used instead of bolts?) so stopped disassembly here and put everything back together to see if repositioning the spring and sector gear would fix anything.

Before putting the cover back on, I noticed that the gear shift shaft was quite free to move out, and so would easily disengage from the cam drive gear.

There is a circlip and washer on the shaft that, once the cover is in place, looks like it is supposed to keep the shaft from sliding too far out.

Once I buttoned everything back up, I was able to shift up and down pretty normally a few times with the engine running, but the old problem cropped up again.  I'm now able to move the shift lever up and down enough to rotate the gear shift shaft 10-15 degrees without any resistance.  Beyond that there's no movement and certainly no shifting.   It feels like the sector gear is once again outboard of the cam drive gear.

I'm stumped.  Any suggestions would be greatly appreciated.

... chirp, chirp,...   ... chirp, chirp,...  


Gears,...      I don't go in there... ...

You have identified your problems, but you haven't fixed any of them.


Go back in there and start aligning and correcting and bulletproofing.


Clymers has whole section on that little gear box on how to realign all the little twiddles and widgets so they work right.


Good luck, never been inside my little shifter box on either of my engines.