Crap, I thought it was the one in the radiator?
So, Im not that much into the function of the cooling system. I know my mechanic checked the thermostat when he had the bike for valve-check.
And I just pulled the left fairing, dried drops of coolant down the generator-cover, and the reservoir was pretty much empty. Filled to max and went for a ride, temp. stable around 77-78 while riding, and rose nicely to 103 when parked and dropped nicely when the fan came on. There were coolantspray again.
So I guess there is a leak somewhere, will have to check later
SP1's use the more simple thermal switch mounted into the left radiator to switch on the single fan, while the SP2 uses a sensor mounted into the thermostat housing which sends a signal to the ECU to switch on the dual-fans via the fan control relay.
Your leak could be from a loose hose clamp, or a possible crack in the left radiator.
I've heard comments from SP1 owners where the radiators are prone to develop cracks due to only two mounting bolts vs. three on the SP2.
Check near the mounting tabs if there is coolant residue nearby.
I had a similar leak problem with my SP2 due to a puncture in the upper radiator tank by the prior owner, who repaired the puncture with JB Weld.
That repair didn't hold due to the radiator flexing with each heating/cooling cycle, and I found coolant dripping down my radiator and onto the ground.
Was able to have the puncture welded and pressure tested.