There is something not right with the Idle system. For a while now I had to run it at ~2500 rpm, whereas the manual says 1200 rpm. However, if I set it to 1200 rpm the engine will surely cut out. I had the bike serviced but driving back I noticed the idle increased to 3500 rpm. So back at home, with the motor warmed up on my drive I set the idle back to 2000 rpm. The next day I set off and during my journey the engine cuts out every time I pull the clutch lever in and revert to idle, the revs go below 800 and the engine cuts out. Only if I reset the idle speed to 3500 rpm or above will it not cut out. My mechanic said he had to rebalance the carbs so I assume that works correctly. This weekend I will check the air feed into the idle system. Any other suggestions?

Carbs - idle jets & or syncing

Thanks for the reply. Yes, idle jets are prime suspects, and vacuum connectors. I had a look over the weekend and squirted some carb cleaner into the air intake. I was lucky, all is running smoothly now.