Frazer once again to the rescue not quite sure what is happening looks like two single acting cylinders with a controller on top. I do understand a DOUBLE acting TWIN will self start but that`s about it. This engine i`m using is not an oscillating one i think the porting is in the shaft and i thought something that you are showing ( first time i have seen it )might be the answer. Maybe i`m dreaming but i think i saw somewhere maybe same site someone made a device that flicked the flywheel extra servo ?. Would be nice if someone had the gear and tried it and let us know i don`t have that type of gear yet reason for popping the question is really i`m trying to think ahead still a long way to go.
Once again many thanks
Best regards