I have found that the vacuum switch on my 1990 Johnson 150 hp (Model TJ150SLESB) has cracked and leaks fuel. From what I could find this used to check to make sure the oil is mixing with the fuel. None of the diagrams or repair instructions in the Seloc manual even show this part and it appears that it is no longer made.

Does anyone know if I need to replace this part (I have found it but it seems extremely pricy to me) or was it something that was phased out and no longer used on these motors?