750 paso chain adjustment

[yellowpaso]

I just purchased a 1987 Paso 750. I have the owners manual but cannot seem to get the cams for the chain adjustment to work. I have loosened off the two rear screws on both sides but nothing moves. Ideas or advice will be welcome. Problem solved. Next problem, one word, two syllables WEBER. Bike is now in good hands for the winter when it will be fitted with a pair of new d'ellorto 36mm phf carbs.