Mercury Service Manual for 1965 and Prior Models plus Illustrated Parts Manual that covers KE7,KF7,LG7 and KG which will be well worth having and close study. If you need parts the parts manual will show you which models share the same part number. Before doing anything, diagnose the probable cause of problem, Do not fix things that are not broken, There are a lot of people in AOMCI who will know the ins and outs of work on this series who will chime in .
Louis
