Hello For years I have had a Bimota YB11 that carries the engine from the Yamaha Yzf1000r Thunderace. The engine now has 26000KM on it and shows the following problem.: When I had the air filter box off the carburetor and the engine was running, one saw on the carburetor from the cylinder 1 an outflowing air (mixture) column ???? In my opinion this can only mean one thing, an intake valve does not close properly. How do I go now best? How can I check the valve play, what must everything to be dismantled ? Thanks