Yes I have the Oliver book-a great effort by John Goodall. My observations from the various reports is that it never seems to be a problem at full throttle, only at fractional throttle settings and especially at idle. I am only speculating but it would seem that smaller fuel charge volumes at restricted throttle settings seem to lack the gas momentum to maintain correct proportionality to each cylinder....but in some cases you get a rich cut, and in others a lean cut-depending on which way the gas flow asymmetry goes....one could almost argue that some form of restriction of the transfer ports or passages would assist throttling. ......didn't Oliver experiment with this approach once-via a lever projecting through the crankcase wall that allowed the liner to be rotated through an arc of a few degrees partially occluding or opening the transfer ports....

ChrisM
'ffkiwi'