Hi, I have recently decided to put the M800 back on the road after a 20 month layoff. In this time it has been started and let warm to running temp etc.
I had charged the battery and checked over the bike for it's MOT when I switched on the ignition to here a ratchet sort of noise from under the tank, thinking it was the fuel pump, I turned it on and off a few times still there.
Took tank off and it turns out it was the secondary butterflies stepper motor making the noise. Butterflies were not wanting to move at all so time to strip it down.
Removed the stepper module and the TP and STP sensors, butterflies still stiff.
Next removed the linkages that go from the secondary butterflies to the throttle stop pivot and there was the problem.
The main pivot has an arm, spring and bronze Bush, the Bush was seized on the pivot pin, some gt85 and gentle persuasion later it was off.
Polished the bore of the bush and coated with moly grease and reassembled everything.
Had to reset the TP and STP sensors.
Bike passed it's MOT and it was great to be on my bike again for the first time in 20months.