Pressurising KV6 190

[murphyv310]

I'm seeing the signs of something not quite right in the cooling department. Running temperature has gone from 93-95 to 97-99 with excursions to 100c with the fan running for quite some time even at 30-40 mph. I've bled the system three or four times but there was no signs of air. What does help though is to drop a couple of gears which keeps the revs up, also running at 2000 rpm in neutral at lights reduces fan run time.
My feeling is poor circulation so I'm doing a full flush with water and then flushing compound. If this doesn't work I can only assume the new thermostat has decided not to open fully when it should.