Well I thought I would chime in on the boost bottle and four stroke thing.
A 4 stroke suffers from plenum float (atomized fuel in the air cleaner floating above the carburetor). All single cylinder and single venturi engines do. I am sure folks have seen Stacks on the top of those webber or solex carburetors on hot rods of the 50's and 60's. You know the ones they put yellow tennis balls in at the car shows to keep those pesky alligators out of the engine. Those stacks help to contain that plenum float so that the individual cylinder, left or right bank won't lean out at certain engine rpm or during a transition from decel to snapping open the throttle.
You would need to match the intake plenum volume, cam lift and duration/ RPM range and stack height to properly contain and control that plenum (pulse) float. Hopped up VW pancake engines have this problem and are still today run as one carburetor venturi per cylinder for hot rod use. They run taller intakes and stacks on the carburetor when they need to control that plenum float effect. I am sure you have seen those 8,10 or 14 inch tall filter risers on motors. These are all acceptable ways of containing the plenum float.
So yes a boost bottle will help with plenum float. It will also richen the mixture at a given speed or plenum resonance or when snapping open the throttle. The boost bottle is helping to create a constant (smoothed out) flow through the carburetor in all engine rpm conditions and especially the higher rpm ranges.
Mostly at the higher RPM ranges is where a stack will help contain that plenum float effect. If the plenum float is not contained or controlled through... multiple pulses on one properly sized venturi (as in complimentary 2 left and 2 right cylinders on one venturi like a Chevy V8), properly sized stack height and diameter or yes a boost bottle. Then top speed, power and fuel economy all will be adversely affected.
The boost bottle will likely be a bad idea however in a cold climate because of fuel vapors condensing inside the bottle and running into the engine as dribbles and not a vapor. So you may want to experiment with stacks and taller air cleaners to fit over those stacks. Remote air cleaners with a flex tube of adequate diameter will also help contain and reuse that plenum float effect too. If the pulses (floating fuel vapor) above the carburetor is not controlled and contained it will be lost and seriously lean out that engine. The problem area of the rpm range is usually at maximum rpm so if that plenum (pulse) float is controlled or contained you will notice more speed because of more fuel at that given maximum rpm. You will likely even notice that you can achieve a higher rpm than before.
Hope this helps
Kep1a
Kep1a