oh about the effect of big spark on our combustion chamber ?
1. we can widen the spark plug gap up to 1.2 mm (believe it or not.. i've seen the spark of this coil still could reach 5 cm gap). The effect ? Read 4 stroke performance tuning book by A. Graham Bell.. it could increase power on high rpm
2. we can add more power by step up the pilot and main jet if the spark makes the mixture of the carb too lean because of the powerful combustion..(remember 'big bang' on motoGP, one single spark to burn all the mixture, we can advance the timing of ignition time so the compression is near perfect)