I am trying to find on line, the electrical diagram for my 1974 40hp merc.I took my motor to a very expensive shop,who didn't fix the problem but left my pockets empty.Any help would be appreciated.<br />PS.<br />Thuderbolt ignition
Don't know if you will find it online but you can find alot of manuals online that have diagrams. What kind of problem are you having? There are alot of OMC gurus on this site that can answer just about any problem you have.
