Going with a colder plug during the summer months, should cause no harm. It might foul the plug with a lot of stop and go, and idling. It may be better for WOT for long periods.Have you guys ever used a spark plug that is hotter or colder than the original? What were the results?
Sweet.UK: Honda CB 400T1 Street bike. 2 cylinders, 4 stroke, and yes, right now I'm using the original NGK 8 (NGK D8EA)