1200S: service time, part 5

In the next photo you can see the stator, the shifter mechanism, the outside of the actual transmission (or gearbox) and the starter pinion at the top/rear of the case; note also the slipper tensioner in the outer primary cover, and the drain hole, visible just under the trapdoor:

You can see (clean) transmission oil has pooled in the bolt heads' lip, this is typical. 

That scumbag of a dealer had lied to me and told me they had "replaced fourth gear" at some point, but I'm actually glad they didn't and that this is an undisturbed environment, and that I'm the first guy to get in here since this motorcycle left the factory.

The shifter mechanism is comprised of the shift-shaft with the actuating arm, the pawl mounted to it, which engages the pins on the end of the shift drum; it is returned to its starting position by a sturdy spring that acts on a retaining plate at the back and a retaining tab that's part of the main shift-shaft. Simple at first glance, not so easy to engineer. The retaining plate I just mentioned has slotted mounting holes, and that's what allows for a critically important adjustment as we'll see further into this long, long story. The "positive stop" feature is provided by a small star-shaped plate with detents machined around its edge, and a roller that locates in each detent, mounted on another arm, which pivots just below the shift drum. All of these components rely on springs, naturally, to return to their starting positions, and each of these springs should be inspected and replaced. In this case all springs are in perfect working order and will be going back.

The next thing to go is the spring at the bottom of the positive stop mechanism. Warning: that spring is attached on a steel post that is pressed into the crankcase casting; if you pry against it with anything but your fingers, you run a real risk of breaking it, and then you'd be in real big trouble if that snapped. Instead, all you have to do is pull it off with your fingers, very easy. 

After that comes the dreaded 'C' clip that holds the detent plate on the end of the shifter drum: in some cases this has been known to be very hard to remove, if so, easy does it, don't get frustrated and just work away at it with a good pair of pliers and a good flat blade screwdriver until you get it off. You'll be replacing this, so don't worry about damaging the clip.

In my case, all I had to do was push it flat against the detent plate, while simultaneously sliding it off its groove with a small screwdriver. This was very easy. This clip has a very pronounced curvature and the way it works is by maintaining (spring) tension between the detent plate and the locating groove.

Harley-Davidson released an upgraded part for this, so if you're replacing yours, be sure to get the right one and not some older NOS part.

The detent plate can be lifted out. Note that this is the upgraded part released in 1999, which can be retrofitted to all 5-speed Sportsters back to 1991:

TO BE CONTINUED...