Sorry, no, I cannot see a way to feed all that torque into the sprocket just by torquing up the nut without having a good condition spline there. Just imagine, the gearbox plus the primary drive multiply all torque produced from the crank to about ten times into the rear chain at the sprocket spline. No way to hope for the effect of torquing the nut. Same with the clutch nut plus its spline. There is only one way to achieve a lasting solution by restoring a PERFECT spline fit with definitely minimal play in it. Imagine, the rear chain pull onto the sprocket tries to dislocate it offcenter and only the spline fit can keep it centered. Any play in there produces wear by rubbing motions at all contact faces.
So really only rescue to the actual Burman question is to get a new quality sprocket , get the gear shaft hard laser welded and machine it to sprocket dimensions as close as ever possible. The gear shaft will be less worn at the rearward face on the spline, so when machining it after welding plan to first clean up these faces and have only the forward faces welded up by laser thick enough to restore the lot to perfect fit into the sprocket.
In case no good new sprockets available, I´d probably get a new soft universal chain sprocket and have the spline wire EDM cut - except you can use a standard broach. Broaching would be less costly but wire EDM is allright, only six slots to cut, so no big deal. Just care for a good finish after wire cutting, roughing and finishing cuts, any rough finish will wear fast and slop returns in the assembly.
Basically laser welding in the internal splines of the sprocket is another way, not so nice to do and best to be avoided . Again, machining will be best by wire EDM as the weld will be necesssarily hard. But I´d rather go for stock chain sprockets, get the spline wire cut, case hardened - and the last step is to machine the gear shaft for perfect fit. You can find carbide milling cutters for 65 HRC material and milling is best done face milling for evenness of faces , all set up in a dividing head. Below photos of laser welded splines and ground , same place for sprocket on B-Rapides.
Vic
So really only rescue to the actual Burman question is to get a new quality sprocket , get the gear shaft hard laser welded and machine it to sprocket dimensions as close as ever possible. The gear shaft will be less worn at the rearward face on the spline, so when machining it after welding plan to first clean up these faces and have only the forward faces welded up by laser thick enough to restore the lot to perfect fit into the sprocket.
In case no good new sprockets available, I´d probably get a new soft universal chain sprocket and have the spline wire EDM cut - except you can use a standard broach. Broaching would be less costly but wire EDM is allright, only six slots to cut, so no big deal. Just care for a good finish after wire cutting, roughing and finishing cuts, any rough finish will wear fast and slop returns in the assembly.
Basically laser welding in the internal splines of the sprocket is another way, not so nice to do and best to be avoided . Again, machining will be best by wire EDM as the weld will be necesssarily hard. But I´d rather go for stock chain sprockets, get the spline wire cut, case hardened - and the last step is to machine the gear shaft for perfect fit. You can find carbide milling cutters for 65 HRC material and milling is best done face milling for evenness of faces , all set up in a dividing head. Below photos of laser welded splines and ground , same place for sprocket on B-Rapides.
Vic