G'day again,
After a bit of thought about this issue, that 'black nozzle' restrictor should slow down the valve stem movement in both directions [opening and closing], providing the diaphragm is sealing properly, on both the valve stem and the edge of the diaphragm chamber.
I see Gadge - because the vac from the intake manifold cant suck the valve up as quick, and the piston pushing upwards would be met with more resistance as the valve faces more resistance to closing (more resistance in the top end of the decomp as the diaphragm can't push air back through the smaller nozzle)
Norm, I have a Pace with the low comp head - still goes hard. But I don't cut tall weeds with it - wonder what difference it actually makes
At least on the 24 you have a big disk for more reciprocating mass
