B31 erratic tickover

[Janacek]

Engine starts easily and runs fine,but has a rather annoying little fault.
Tickover ignition retarded is good and steady and feels as though it would tickover all day.Ignition advanced the tickover speeds up as expected and is steady for six or seven seconds and then slows down and will stop unless I blip the throttle.It will then tickover steadily for another six or seven seconds and keep repeating this slowing down.
All jets are as per the book and there are no air leaks.Altering the slow running airscrew makes no difference to this slowing down.Any suggestions?

[limeyrob]

Sounds fine, it shouldn't tick over on full advance. I know its not ideal but if it ticks over at half retarded it fine and safe to ride.

[Derek996]

My ZB32 ticks over very evenly with retarded ignition but less so on full advance. It doesn't stop though. Perhaps increasing your idle speed by a tiny amount will help.

[scifi]

You need retarded ignition at low revs, and increasing advance at higher rpm.   This is the way automatic centrifugal advance and retard works.

Some cars have a further automatic adjustment, which varies the ignition timing with inlet manifold vacuum, so that when you floor the pedal, the vacuum decreases and slightly retards the ignition during the acceleration period.

[V500]

Sounds fine, it shouldn't tick over on full advance. I know its not ideal but if it ticks over at half retarded it fine and safe to ride.

Mine ticks over at a suitably low RPM on full advance, and then can be slowed right down with a little retard.