[Montesa dies with full throttle]

6 hours ago, jonnyc21 said:

One possible cause could be that the throttle position sensor thinks your going past 100%.  Try using some superglue to fix a thin washer or something to the stop to see if it will stop doing that, if so its a position sensor issue.

Another possible cause might be that your t-bag filter is plugged, though that seems a bit less likely based on what you indicate is happening. 

Thanks´i will try, Where do i place that washer, under the gas cable, or ? 

[Montesa dies with full throttle]

11 hours ago, kurtas said:

I'm assuming you have a 4rt.

Why are you turning the throttle very fast to "full" speed?

What happens if you turn the throttle very slowly to "full" speed?

If i turn it slow, there is no problem (seems) 

[Montesa dies with full throttle]

Hi´  

When i turn the throttle very fast to "full" speed, the engine take some RPM, but then it dies, sounds like "drowning" it simple stops if i keep holding the throttle on full. If i loose before it stops, it comes again. I changed the sparkplug, cleaned some electrial parts, and cleaned the air-filter, but it didn´t help.

Any good advice is welcome :-) 

Poja.