How many shims should there be?

I've got 3 shims & was told one was removed before I got the engine, is this correct? Should there be 4?

Temp 11c / 52f

I don't have any no. 5 plugs!! I've never needed them in the last 7 years running .12's.


The engine runs fine with the glow starter on it but now, with the new settings, it cuts out the second I remove it.

I'll try again with a leaner bottom end.