Overheating NC35 with nasty noise!!!

[oliross]

Hi guys, new to this forum, i've done my hello bit in the welcome section so... Recently bought an NC35 and within a couple of weeks the temp gauge has been going all the way to H, everytime i've taken it out since it carries on doing it, Ive changed the thermostat as it was unservicable, the temp sender, the bottom rad as it was knackered, the rad cap and its still overheating, the noise it makes is a bubbling noise from the expansion tank once i turn off the engine. The only other thing to replace is the pump. i have noticed water spray on the rear R/H side of the bike a few times but it's very slight and it doesn't appear to be coming out of the overflow from the tank.
My other symptom is that when i floor it in 4th and 5th the temp goes way down but the moment i close the throttle the gauge goes back to H even though im still going quick and the airflow is still going through, Water pump????? Or Head???? No emulsification in the oil but it is using water.

Thoughts
Oli

[CRM]

sounds like head gasket gone.
take off the rad cap and when you rev it can you see the coolant moving ? should drop a tad and shimmy as you rev it.