I have a 2011 Like 200i currently just above 3,500 miles I ingot it at 2,000 miles and it had been sitting in a garage for years with no known issues ever. At first it wouldn't start or run until belt/disc that moved up and down cleaned, fuel injector changed, spark plug changed, and throttle body/sensor changed. It's been running great but recently I noticed the engine will get a weird higher pitch like it's trying harder then yesterday at a light it just went and cut itself off, when I got home I changed the oil because it was due and then it wouldn't start at all so I changed the spark plug then it would start but the engine sounded weak and sick and evil, eventually if I cranked it on the evil start it would get to sounding normal for idling but I just rode about 15 miles then it started to sputter as If I was tapping the brakes jerking backwards for a split second then immediately full speed then it became rapid unless i was barely throttling for a few miles until it made a weird sound and stalled unable to accelerate and then the engine cut itself off, only maintenance I've done is spark plug changes and oil changes so I don't know if im missing something or I'm usually driving full throttle and don't know if I'm hurting tbe engine because this is my first bike, it usually goes 40-45 mph but pushes 50 if all the way cranked but I've worried if that's like going 100 everywhere in a car. I'm confused and lost on this and deeply appreciate any help
Update while broken down I took off the seat and the sleeve that goes over the spark plug had come off which easily explains not starting, I noticed before leaving too it felt like the spark holder wasn't fully fitting in place and wanting to slide off, could this cause issues besides starting?
