Just been setting idle mixture and found the revs keep dropping, cyclicly, when idle set high.

Car is running a little hotter than usual.

No carb leaks.
Is same with crankcase blowby recirc circuit blocked.
No coolant leaks.

???

Slightly smoky crankcase gases

Thanks for not answering that. Mental block

Err how about not setting the idle to 1200? Anything beyond standard is a modification and the engine cannot be expected to work properly. Does it work at the specified idle?

What does hotter mean? coolant temp? Surely this is unrelated?

When throttle lever rests on the idle screw the solenoid is active, it closes over 1500rpm in this condition.
Supposed to pull the wire off the idle screw when setting mixture.

I think my thermostat is jammed 70percent open.
Plus radiator is 20percent dissolved away.
It overcools at speed and undercools in traffic.

I reckon the smoky crankcase might have been due to lean mixture (leaking baseplate) equals hot pistons- coupled with cheapo dino oil and the cooling issues.
Come to think of it it is oil time.

Have a stock of parts coming to cure all this. It's just symptomatic of pepped-out ancillaries+bit of density on my part.