Hi Tomasz
I've skimmed 1.1mm off my Panda Head, and I have to Use Premium grade Petrol with a Little Octane Booster added or Else I get Pinking, so I wouldn't go Past 1.0mm another time. I've now fitted my Dellorto 40 DHLA Carb. instead of the Solex one and the Difference was amazing, it made the Engine real Smooth and No flat spots when accelerating Just Smooth and Powerfull. I'm next going to fit a 40/80 Cam. as I'm assured that's the one to go for by Toto, and He's been right on everything Else so Far, so He Know's what He's Talking about. The Heat is getting Real Hot now even with a Cav-Mac Cam cover and Big Abarth Sump for oil cooling, thinking a Oil Cooler is the way to go.