Servus Hello, Now it’s so far. My son has stayed with his NRG. According to his statement the scooter went out under the ride. When he is cold he jumps after biting also briefly. Today I tried again which also worked without any problems… Only somehow the whole garage smelled then somehow ….Hmmm… Heiss-metallic. Then I did the work and looked at the cylinder. After the head was down you really didn’t see anything. N Aja then I freed the piston from the cylinder and then I found it (see pictures). No idea where the monster bars come from but they are there. Cylinders and pistons are already ordered. Now to the actual question … Does a piston have such a color? I look strongly after overheating by no or too little oil. Or what do you mean? I have to say that my son is such a patient who has no idea and it can also be that he has any engine oil in the n oil tank has poured what he would of course admit Nieeeee. Can one check an oil pump? Before already many thanks