Yesterday I was stwuggling. The kick-starter mechanism was the culprit.
Long in the distant past with my old British bikes (and even my current MZ) the kick-starter mechanism was a geared quadrant that engaged with the gearbox main shaft when the lever moved off its stop. When the engine eventually fired a ratchet engaged and stopped the engine driving the kick starter lever round in circles. When the quadrant was disengaged, when the lever was on the stop, there were no moving parts and the clock spring (pre-tensioned on fitting) held the lever on the stop. Simple but effective - each component had one job and each was stationary when disengaged.
The problem I have with the Morini is a kick-starter that does not return to its stop after use, rather it droops under the weight of the lever and secondly the ratchet is obviously engaging even with the lever on its stop.
Here is a picture of the arrangement:
The components working towards the centre-line of the engine are the lever itself, the shaft, an O ring, an outer spring collar, the coil spring with two tangs, one of which goes through the outer end of the shaft and obviously tensions the spring when the lever is operated, and the other tang (the fixed end) which engages on a post which slides into a hole in the main crankcase. Next,after another sheet metal spring retaining collar, there is a heavy component that is splined onto the shaft and has ratchet ramps machined on the inner ward face These ramps engage with ratchet ramps on the outer face of the kick starter gear itself. This meshes with a corresponding gear on the mainshaft. This kick-starter gear, I think, spins on the kick-starter shaft all the time the engine is running.
As far as I can work out the spring in the Morini design performs two functions, as soon as the lever is moved off the stop the tension increases encouraging the lever back to the stop, the second function, I think, is to manoeuvre the splined ratcheted component into engagement with the ratchet on the outer face of the kick-starter gear.
I must have had the assembly together with the outer case on and off about 5 times yesterday. You need to put the case on in order to set the pre-tension on the spring. I set it exactly as per the manual and the lever drooped and the ratchet was still engaged, I tried it with varying increasing levels of pre-tension on the spring and whilst the lever rather lazily returned the ratchet was solidly engaged.
After a couple of hours and before I took a club hammer to it, I walked away.
Writing this down has helped me work out what I think is wrong.
1. As the ratchet is always engaged to a greater or lesser extent, the kick starter gear is c 3mm too far away from the centre-line of the engine. It is snagging on a wear mark on the shaft and cannot cam out of the ratchet sufficiently?
2. The fixed end of the coil spring necessarily must move along the post when the kick starter lever is activated. There is the possibility that this fixed end of the spring is snagged and cannot move back thereby keeping the ratchet engaged?
Guess what I will be doing today?
PS The manual I downloaded is for a later year Morini and shows a drawing of the set up of the spring. The fixed tang of the spring in the drawing is the opposite way round to the spring I have inside my gearbox????