dont think its the head gasket mate,cooling system seems to be working wrong way around the rad empties to fill up the expansion tank If rad and expansion tank are full theres enough coolant in the system so bike doesnt run hot,i drained the system and refilled let the bike run with cap off etc,checked thermostat and water pump and both of these are fine.Still the same.
can i run bike witout expansion tank,ive seen hrc coolant bottle mod listed in the marketplace?