So a Mk3 been stood a while but now starts well and revs freely. Clutch disengages but a bit sticky. So when putting it into gear the engine cuts out even when revving the nuts. It like a switch, I don't think that it is the clutch sticking. Any insights or solutions much appreciated.

Sounds like the side stand switch is faulty. Its quite easy to bypass, not sure if they are still available.

https://www.cmsnl.com/honda-crm250r-199 ... 700kae305/

As above

The side stand switches are fairly standard accross Hondas from that era. I bought a second hand one off a Honda four of some description. It worked fine though I needed to solder on the lead from the old switch as the connectors were different.

Keith