Could it be coils

Ok, the gixers got 30000klms on it and after taking it to stage 1 i.e. pipe and filter I put it in to have the carbs / jetting done. Bike has run well once since, it keeps fowling the plugs. Mixture is not rich, does not use or burn oil, all leads have been tested and are good. Running hotter plugs now to keep it going 7's. The original coils are still in. What do you guys think?