Thats because to set it properly you need a timing belt tension tool.
However if you twist the length between the cam and the water pump it should be able to turn about 90 degrees with resonable force. If you are worried take it to a garage to have it checked with a proper tool.
Also remember that the 16v fire engine and also the 1.6 and 1.4 engines are damaged by timing belt failures its only the 1.1 & 1.2 8v that are clearence engines.