Coolant

[returning rider]

I flushed mine a couple of times as was filthy took the rad out back flushed it I just used generic coolant (Prestone) that was safe for aluminium engines, use the same in my sons bikes and had no issues to date

I wouldn’t go messing with pipes and taking the rad off for fear of some sort of exhaust stud- gate. I know it would just go sideways.

I had no real issues be gentle with hoses and all cam off ok needed it was full of black gunk doubt it had ever been changed