RE: mcculloch 32cc timing ?
The SPE 26 and the McCulloch 32 I have are extremely low compression with small ports. 40 degrees just starts to kickback. 28 degrees loses several hundred RPM the top end.
Any sort of chainsaw derivative / DL / fourstroke glow conversion / twostroke glow conversion would bite your hand off at 40 degrees - I agree!
Bike four strokes typically advance to 40 degrees.