That's another thing I forgot, after each step, when playing with carbs, balance them.
As far as the driveline thing, it's a chain. Chains can only pull, not push, so when you let off the throttle, the tension has to switch from the "top" of the chain to the "bottom". Proper adjustment of a chain DOES involve some slack. Has to, or else it would snap. So there will always be a little bit of a snatch like that.
