I need wiring diagram for 1968 Evinrude 55Hp Outboard to replace colour coded motor wiring diagram.

go google and type in ---owners manual for evinrude 1968 18hp outboard --and there are several sites that have the manuals for down load

evinrude 1978 -1979 have a capacity discharge ignition unit as the control for the spark system
it runs wires to an ignition coil
so I would be suspicious of that unit
check all connections for corrosion and bad connections
I typed in electrical schematics for 1978 evinrude out board engine and found a site --www.maxrules.com which in the list of schematics has 55hp 1977-1978
press on that and you get a schematics of the wiring diagram evinrude 1978-1979 55hp
now I am aware that you state that yours is 35 hp but if it has 2 cylinders then it is a fair bet that the wiring diagram will be the same
any way there are plenty of other sites that may be of benefit

Check here,

http://www.kicksup.com/evinrude/

Take the cowling off. Also drop the foot. There wil be a stainless linkage rod that runs the length of the motor that you will have undo to drop the foot. The water impeller will be inside a stainless casing that you will have to disassemble.

Some of those had a battery ignition with a short cap and rotor, and some had a magneto which reached down into the bucket. Both had points and condenser like an old car. The cog belt location was critical. 2 teeth off and it would not fire. the key switch was wired diferently for each ignition system.

Seloc has the best manual.

Here is a link to the diagram you need.
http://www.maxrules.com/graphics/omc_pics/wiring/61_66_40HP.jpg

Hi there, You can find all parts diagrams for Evinrude engines here: http://epc.brp.com Just ignore the email entry part and go straight to the database. They are listed by Brand, then year, then HP size. I checked for you and it has the 1977 85HP models listed there. Then just find the right subsection of the outboard and it will bring up exploded diagrams for your viewing!