I have a dt125r year 2000 and I have a problem that it fails after 7000rpm, like if we cut ignition and then restart and then fail. The engine was rebuilt with a new piston but the problem is still the same. In the document it have a 7.4kw and I had other two ones from the same year but they had 11kw writed. Do You have idea about this problem? Regards carlos

engine stalls on the fly driving ,
has huge causes.
do head lamps die too , at same time?
does a fast right foot save it? or delay it or even cure it. ???????
do all electrics die or some only?
does it restart easy or only if let cool off the engine ( or restarts easy)
ever get a tune up in 18 years spark parts, filters all?

engines can sure do that for vast reasons even 50.
in macro form, a bad engine, bad spark , bad fueling, in that order.
there are many tests, for all that ,like 3 years of ASE study.
1: fuse blew and stalled, even pump fuse. but will not restart.
2: engine bad or just EGR stuck open or cats melted but again does it restart or even run cold to fail later, if does skip this. most times.
(keep in mind seen cylinders fail hot, valves in head stick open hot)
engine overheated some models of car, my 04chev, even cuts dead cylinders if engine overheats or even stalls it, as to not wreck it self.
3: bad spark, if ECU sees spark hard fail it cuts fuel, fix spark.
4: loss off fuel or too much./ too much floods engine, injectors stuck open or go dead/

there are a bevvy of tests to do in order.
just get it serviced if dead now say so
dead engines are easy to diagnose, and 10x safer too not moving.

I have heard of ignition failure sensors but only in connection with oil or gas-fired space heating units.
I have been around vehicles for 42 years and I have never heard the term connected with vehicles. If the ignition fails it is rather obvious as the engine stops or fails to start.

The closest thing is the ECU that is programmed to deduct when misfiring, high or low voltage conditions exist.

With it just stalled you need to isolate the problem to fuel spark or compression to know that to do next. no spark inghtion modules fail. no fuel fuel filters and fuel pumps fail. Compression cooling system problems ( no fan) raditor coolant low) therostate stuck clossed. find something and reply and I'll be glad to respond to your post.

try removing battery and cleaning all the ground under the battery tray and check main ground wire from battery to engine