i didn't replace anything so i dont think so. This is not my area of expertise. I just had the urge to give the cleaning a go. the carbon brushes were tricky to get back in place.
If the cleaning didn't work my next stop wouldve been an automotive battery and starter service place not too far from where i stay. But, so far so good. going to stick to riding fairly close to home for now. but looking forward to hitting some better roads further out soon. riding feels good🤙
Sadly, my problem is back. I think I may need to take my bike to my local motorrad or bike shop to have the starter and any other electronics checked. Sadly I just dont have the time tinker with it myself. I got stuck yesterday after making a quick stop on my way home. Turned the bike off and it wouldnt start again. Just a sluggish turnover, like a dead battery. The problem seems to occur when the bike and starter motor is hot. So I waited maybe 3-5 mins and tried again, no start. Then i decided cool it down by pouring some water onto the starter motor while leaning the bike over. Hit the start button and it started fine.... maybe a new starter is due, or i may take my one to be refurbished by a professional. (New aftermarket one. BMW seems unnecessarily pricey)
For what it's worth, the mechanic I go to thinks the earth is under specified, so heat is precisely the problem, creating excessive resistance. He added a secondary earth cable roughly a year ago and I've not had any problems since. It is still slightly sluggish turning over but it seems to have tipped the scales so it's never not started once hot, since then. Might be hocus pocus I've no idea, but it's worked for my ride - still on the original battery on a 2014 R9T, optimate on whenever possible...