Vmax and xenon

Hi, my brother picked up his TTR 225ps today 1st hand 40k km and after proper warm driving on the highway he runs unfortunately only 240 km/h according to the speedometer.(doesn’t run great otherwise no stalling and jerking) Now it’s definitely on the LMM when I read the forum like this. What do you mean? Should we pull off the LMM and test Vmax again or wouldn’t that be so good for the engine? Or what else could it lie on? And one more thing, the car has Xenon light and left next to the steering wheel a light wide enregulation is that normal ? That should actually be automatically controlled at Xenon is in any case so in the manual.