Originally Posted by
Roelof
So it is all about the inertia giving a better push when going to the seccond gear.
Or is it just that we are already low on weight with the clutch (lightened flywheel and aluminium clutchbell) that some rotating weight is needed again to get a more stable running engine?
Yes, correct for the inertia.
Since the clutches are getting lighter the inertia is less. Indeed a heavier flywheel could be a solution but it will take more time for the engine to spin down in rpm when you close the carburetor. For sure a little(I mean just a little) heavier flywheel would not hurt.
BTW this is what they start to do in Off-Road sometimes.