If the boss on the new sprocket has less distance verses the original sprocket, it could bind on the crank case.....The C 19 shim washers for the clutch main shaft nut will fit over the output shaft and space the sprocket outward to give running clearance. However......If the new sprocket was a tight fit on the output shaft requiring a bit of assistance with a hammer and alloy drift or similar, it is very much possible the output shaft bearing has shifted inboard and this will cause the sprocket to sit more to the left than it should......A simple plate and using the sprocket nut to act as a puller should pull the bearing back to the right if that is the case.......The G 3 input shaft mentioned earlier should have about 20 thou end float with the mainshaft nut undone.......more is not necessary and less will restrict the ability for gearbox oil to enter and lube the output shaft bushes. This should all be done with the G2 cover in place with some attaching screws to check this end float,...... remove the cover one last time to apply some sealant and all the screws tightened fully home.
