Meshed in..if you play with it without the spring, you'll see how it works.
It's there to absorb any sudden torque action from the crank under load, and to a lesser degree from the wheel under deceleration.
Other bikes have it in different places, rubbers in the back wheel, or the clutch, and Moto Gutzzi have a surprisingly similar setup on the input shaft in the gearbox.
I was wondering why the primary chain was such a hassle, unless it's a endless one, whereby you need to fit it to the engine sprocket and chainwheel and add them on the shaft simultaneously.
At risk of stating the obvious and to save time....:...-
If it's a split chain with a conn-link, totally back off the adjuster so the bottom roller run is a straight line across the tangents of the sprockets, and have the join at the top above the adjuster plate.
There's a bit of a recess in the casting, and if you hold your tongue right, get one pin of the conn-link in halfway and then slip the other end on.
Then add the intermediate (thicker) plate, and then slide on the outer roller runs.
And don't forget the outer plate is thinner, and make sure the open end of the connlink circlip is facing AGAINST the direction of travel
.....too easy......?
Nb It also helps to jam the chainwheel so the weight of the chain don't work agaist your efforts....more
