Tuning Uno breaking up on high revs

[Zian]

Hi, my fiat uno 1.1 fire breaks up on high revs when reaching about 80-100km/h in 3rd gear. When going slowly through gears to 80-100 it doesn't break up. Only when full throttle. Already rebuilt carb and didn't fix problem. Any advice? Thanks.

 

[jackwhoo]

Ignition system

 

[Zian]

When in 1st and 2nd gear is doesn't break up only when shifting to 3rd gear.