Thanks for the reply, I now know about the main jets, it is probably 105/102 and my 1987 has (what I remember) 107/105. The airbox there can be a rubber membrane and smaller holes in the top (looks like a snorkel) on my own its a small dividing wall, the swiss model should be about 1-1,5cm thick. The exhaust I’m still can’t get a prober answer about 🙂 somebody says it the same part number as my own 1987 bike, others says the exhaust is restricted.
But maybe I just ride it as it is, because the condition its so beutiful compared to my own bike. (the new bike seriosly looks like it was produced yesterday) 😀