Hi there I have taken charge of a 1979 honda cb750kz in reasonable nick and have slowly been replacing parts and cleaning etc however i did notice that the end of the camchain tension adjuster at the front of the block has been filled with silicone as the plug is missing. Having purchased plug and removed silicone I popped the plug on but it didint sit flush with a couple of centimeters sticking out . Is this normal or should it infact be flush. Please help. Thanks