New Drive Sprocket

Basic question, and I think I know the answer. On a Mk3, do I need to remove the entire primary and inner primary case, to replace the final drive sprocket? No way round it?

I spent ages getting alignment and oil tightness last time. Looking to avoid it if possible!

The joys of Norton ownership Yes, full strip down.. IIRC I aligned the sprockets on reassembly with two short straight edges rather than one long one as usually shown/suggested. That way any discrepancy can be seen at the overlap...

Start a' strippin ' !
Ideally you should replace all 3 components . The mainshaft sprocket , the chain , the final big sprocket .
The one we are discussing takes the most forces and wear . Then the chain . The final sprocket takes the least wear and can be reused if the teeth remain healthy .
Wear disposable plastic work gloves .
Enjoy the job and adhere to the manual torque values .