Parts for the old 675's are getting harder to come by, which is why they are so expensive. What's wrong with your assembly?
It sounds like you just need a new pump and not the whole assembly. You can find them cheap all over ebay.It's not getting enough push to the gasoline or something like that. It's struggling to get gas. When we put the meter on it. The readings was low which told us that we needed a new assembly.