1998 Integra GSR, replacing water pump. The sprocket diameter on the new OEM water pump is smaller than the existing Honda one. After installation of thenew pump, the existing timing belt now is too loose. Existing Honda belt, which is fine with the old Honda pump, is used and tensioner adjusted for maximum tension, but still has too much slack. Is there a trick in adjusting the tensioner? Does anyone know if the smaller diameter on the new pump is the problem or is it something else? Thanks in advance.