Now that the season is over and work can start on the bike I decided to build a new engine with a lighter flywheel after having much thought over the pros and cons of flywheel weight. There is much in the way of arguments for ' heavy' as the momentum gives explosive acceleration due to the kinetic energy stored in the flywheels when the lights turn green.
However I am experimenting with a badly corroded set of flywheels so they would have needed dressing anyway. I loath turning cast iron as it comes off as crumbly dust which gets everywhere. I have heard of people trying a magnet at the tool to try and collect it but I just brush it down.