Young sons xmas present fouls plugs after 30 min riding.He only hacks around in 1st gear but revs are up.I have also fitted a 'throttle stop' to avoid him getting full noise at the moment.The bike now lives at 1200ft above its previous home at sea level.Can plugs be rejuvenated?Any help would be greatly appreciated.Its such a neat bike and I am hoping he can grow into it,cheers!