Hi,

I have dismantled my MC21 engine ready for the bottom case to be welded, and then a full rebuild.

Naively, I did not undo/remove the water pump impeller whilst the engine was still together, so I now have the impeller and shaft assembly still fitted in the RH case, which need to go off for vapour blasting.

I am now struggling to undo/remove the impeller from the shaft. It does not want to unscrew, and due to the issues with replacing the shaft and the plastic gear, i am being extra careful not to damage anything.

Am i right in thinking that the impeller should just unscrew from the shaft itself.

I looks like it should on the parts diagram, and checking the torque setting on the manual (1 kg-m), it should come undone pretty easily but isn't.

Any ideas?

Many thanks,
Max