Hi guys.
I have a little problem that is giveing me a headache

My Tenere (1vj) has started to miss out, When I keep constant speed (any speed) for a longer time it starts to jump every now and then.
If I give it some trottle it runns perfectly agian for a while. Itīs very annoying,specialy in rush hour traffic.
I cleaned the carbs and the tank, didnīt help much. Sorted the carb adjustments, didnīt do any differense. Put a new sparkplug in today, still the same.
I tought that maybe some one here would have an idea to what it might be before I dig deeper in to the carbs or ignition system.