Thanks for the tip. I found the Westerbeke Manual for the WMF 25 here:
http://www.marinepartsexpress.com/Westerbeke_Manuals/33620-20.0,25.0,32.0WMF,%2020.0,21.0,25.0,26.0,32.0WTA,%2032.0WTF%20Parts%20Manual.pdf
Sure enough, on page 65 is the parts view for the injector pump which shows the...